Inner Cover/Top Liner

Pros: Reduced road noise, Increased insulation, Folds away neatly without affecting the use of the boot cover
Cons: Slight loss of head room, Maintaining a “perfect” installation requires occasional adjustments
Cost: $329

I love owning a convertible, every chance I get to drop the top I take it. However there are times when the top must stay up because of rain, extreme heat, or extreme cold. There are pluses and minuses to everything, and it is during these “top up” times that the minuses of owning a convertible become evident. I always thought the Z3 top did a fairly good job, but my only previous experience with a convertible was a 1980 MGB. The Z3 top was clearly better than the old MG one, but then I saw a real convertible top. Some friends of mine had just taken delivery of a new 3 series convertible and invited me over to take a look at it. After seeing and experiencing the top on that convertible 3 series I noticed the key difference. That 328ic had an second inner layer to the convertible top. With two layers instead of one the 3 series top looked better, you couldn’t see the metal frame because it was hidden between the two layers. The extra layer also appeared to cut down on wind and road noise as well as provided more insulation.

The top on the 3 series was clearly better than the top on the Z3, so the hunt began for an aftermarket inner liner or an altogether improved convertible top. My efforts didn’t turn up anything, about the closest I got was at the 1998 Z3 homecoming. The producer of the Z3 top attended the event so I asked one of them what the chances were of getting a top for the Z3 similar to the top on the 3 series. They said they would look into it but seriously doubted that they would be creating such a top. Imagine my surprise when not more than a couple months later MG Racing posted a message on the Z3 message board about an aftermarket inner liner specifically made for the BMW Z3. The liner claimed easy installation, decreased road/wind noise and increased insulation all for $330.

After exchanging a few e-mails with MG Racing a gray colored liner was on its way to Dallas. Once it arrived I opened up the instructions and got my first real look at the product. The instructions were pretty straight forward, they described how the black plastic parts replaced the current ones on the Z3. They snapped on over the support ribs in the top and held the liner. The rest of the installation involved velcro straps that wrapped around the folding metal frame and held the top in place.

The material was thick and soft, it reminded me of a high dollar college sweat shirt. After that initial inspection I knew the product would cut down on road/wind noise as well as provide insulation, the only remaining questions were the installation and how it would handle the folding top. My primary concern was if the top could still fold down flat enough to use the boot cover.

Sold By:

MG Racing

http://www.mgracing.an/

800-788-1281

Installation

The first part of the installation was to remove two of the existing black plastic sleeves from the convertible frame and replace them with the sleeves that were sewn into the inner liner. There is a glue like goop under the plastic sleeves that helps holds them in place, so its best to start on one end and slowly work the support off. When installing the replacement support I would rotate the sleeve slightly so that the stitching is slightly rotated forward instead of facing straight down (I’ll come back to this later when I talk about tweaking the installation). This part of the installation should be done with the top unlatched and slightly opened to reduce tension. It’s important to get the support centered, I just eyeballed it the first time and later had to go back and make adjustments.

The next part of the installation involves working with the various velcro straps to finish securing the inner liner to the frame. I would suggest opening the top up a little further while you work on the side straps. The instructions do their best to try and explain in words where each strap should go, but a little trial and error was needed for me to get it installed. Resist the urge to get each strap as tight as possible.

From this angle to can see how the liner is attached to the frame, at this point I had spent a lot of effort to get each strap tight. Later I realized how loosening up the straps let the top hang straighter and fold down with less tension. The one gap that you see I was never able to get rid of, but when sitting in the seat you don’t notice it. This is also the side of the top that has the additional frame pieces for the power top. I think the liner is really designed for the manual top because it doesn’t fit as well around the additional power top mechanism on the drivers side. It fits much better on the passenger side which doesn’t have any additional items related to the power top.

Once you get the velcro straps on the side secured there are a couple in the back. These were somewhat difficult to secure because of the close quarters back there and you really can’t see what you are doing. I found it easier to sit backwards in the seat and reach back into the opposite side area (ie when sitting in the drivers seat work on the passenger side and vis versa). Remember that tighter is not necessarily better when working with these straps.

The last step of the installation secured an elastic strap to the frame. There is a plastic pop-rivet like thing that comes with the top liner. It pops into an existing hole in the convertible frame. The elastic helps keep the liner tight in the corner and a piece of velcro on the strap holds the liner down.

Once the installation was complete I sat in the Z3 and gave it a visual inspection. I could see areas that seemed too loose or too tight, but basically it was there and looked pretty good. I like what it did to the interior, the gray material lightened up the interior and made it feel bigger. But I could tell that my installation needed some adjustments.

It was time for the real test, how would it handle lowering the power top. I was especially concerned about the tops ability to fold down enough so the boot cover could still be used. With the uncomfortable sound of velcro tearing/loosening the top went down, the installation really needed adjusting. However despite my obviously sloppy installation the inner liner folded away neatly and somehow folded just as tightly as it did before. The boot cover could be installed without any problems. When I raised the top back up most of the velcro straps that I had spent so much time tightening were now loose, it was time to tweak the installation.

Tweaking the Installation


The droop over my head needed tightening because it would occasionally touch my head. When I looked at the area over the passenger’s head there wasn’t a droop. I concluded that the plastic sleeve in this area must not properly centered. Once I centered it the droop was less on the drivers side but more so on the passenger side (the key is that after getting the snap on support centered the two sides were now equal). Once I had the two sides equal I found that rotating the plastic sleeve tightened up this area and got rid of both droops. You can’t actually rotate the sleeve because of the glue like goop stuff under the sleeve, so by rotate I actually mean remove the sleeve and reinstall with it slightly rotated forward.It was obvious my installation needed some adjustments, There were two things that were bothering me. The first was a droop in the liner right over my head, the second was the velcro sound when the top was lowered.

I then turned my attention to the velcro straps on the side, what I discovered is that tighter was not necessarily better. By loosing the straps the liner was able to hang straighter and it actually made the top material fit better against the frame. The now looser straps also allowed the liner more flexibility when it was being lowered and folded away. This cured the velcro tearing sound when the top was being lowered. The secret is to let the material hang naturally and then secure the velcro strap so the material continues to hang there. Don’t think of the straps as tie downs but rather rather as supports during the folding process.

Conclusion

I’m pleased with the end result, however if I had it to do over again I probably would have chosen a black liner. I like how the gray liner makes the cabin feel bigger and less confined. However the lighter color also shows every detail. This is why I’ve been so picky about the installation and felt the need for additional tweaking. That is because I can see every fold, crease, tuck and strap on the light gray liner. I’ve seen the exact same liner in black installed in a Z3 and you really can not see any of these details when it is black on black. I also wonder what my gray liner is going to look like after a season of top down driving, I suspect its going to need a good cleaning since it will probably be a brownish gray from all the dust.

This hasn’t really affected me, but it might affect some Z3 owners over 6 foot. Since the liner hangs on and below the frame, you lose a little head room. I adjusted my seat up just to see how annoying it would be if your head made contact with the liner. After only a few minutes my hair looked like Kramer’s hair on Seinfield (stood straight up).

The liner really does cut down on road and wind noise, even more than I expected it would. I think the softer fabric has also increase the acoustics inside the Z3, I have no way of proving this, but to me it appears that the stereo sounds better. I can’t really comment on its insulation capabilities at this time, I live in Dallas and even though its Thanksgiving weekend its still 70 degrees here. I’ll update this article again once the cold weather hits, however it would appear that this liner will make quite a difference. I guess the bottom line is that the liner is probably a wise investment for the winter months, especially for those who live in colder climates.

BMW Roadster Tonneau

Pros: Installs Easily, Covers Cockpit, Lightweight
Cons: Requires Boot Cover
Cost: $78.90 (with shipping)

I’ve always been in a love/hate relationship with the roadster’s boot cover. I liked the way the Z3 looked with the boot cover installed over the folded down top, and I recognize the protective benefits of using the boot cover. However it is such a pain to install that I seldom used it except on long drives (when I knew the top was going to stay down). The problem was that I was never comfortable enough to leave the car parked with the top down. The exposed leather interior would be subject to bird bombs, harmful UV rays, dirt/dust, and prying eyes.

Back in highschool I drove an MGB that had this great accessory called a tonneau cover. This thick vinyl cover snapped around the cabin of the MGB on specially designed snaps that were part of the interior. That tonneau cover effectively covered the interior of the car and it was much easier to take on and off than the convertible top was to put up and down. The other really neat feature is that it had a zipper down the middle so you could unzip just the drivers side and drive the car with the tonneau cover still in place. I’ve been wanting a cover similar to that MGB one for my BMW roadster every since I first got the car. However no one made one, and from a development standpoint since the car wasn’t designed for one chances are it would never exist.

M&M Marketing produced a car cover that was very similar to what I was looking for, and I almost got one. Except the M&M design is really closer to a car cover and I never really cared for the looks of it. From a utility standpoint I’m told that the M&M design works well. It stands up okay to the elements and is moderately easy to take on and off. But it just isn’t that attractive to look at (to me it always looked like a small tent had been pitched over the car). I’m told that the M&M cover is actually a Miata cover that happens to fit, but sometimes it looks just a tad too small to me.

Apparently Carter Lee had the same thoughts and undertook a project to design a simple tonneau cover specifically made for the BMW roadster. Carter’s design fits flush with the dash and it is custom made for the Z3’s interior. There are “pockets” designed to go over the seats and dash pod. Carter even designed two different versions to account for Z3s with and without roll hoops. Carter’s design was not the same as the original MGB tonneau I had always wanted, but it was so close that I just had to have one.

My first indication that Carter had gone all out in making these was the very professional packaging that arrived shortly afterwards. However, after admiring his packaging handy work I immediately ripped the bag open, tossed the instructions and went out to the garage to try it out. Initially I fumbled around trying to figure out the best way to install it (guess I should have read the instructions first). But finally decided that I like to slip the custom pockets over the seats, then get the front of the cover tucked in, secure the sides via the velcro straps, and lastly tuck the back of the cover into the crease at the rear of the boot cover. First couple times took me a few minutes but now I’ve got it down pretty good.

Basically there are four places in the design that attach the tonneau to the roadster. The leading edge of the cover has a foam like trim sewn into it, this is designed to be tucked into the area where the windshield meets the dash. The foam slips into the crack with a push but then expands and secures rather well. Around each side mirror the tonneau cover has two velcro straps that secure the tonneau to the mirror. This works well but does require that you leave the windows down. In the back the tonneau cover tucks into the convertible top storage area along the trailing edge of the boot cover. This leaves a nice smooth taught look, I’m told by Doug and Eileen Morgan that it even keeps water out of your interior should you get caught in a quick shower (however it shouldn’t be considered an acceptable cover if you are expecting a rain storm).

With Carter’s tonneau my MZ3 finally had a cover that matched its sleek styling. The tonneau fit nicely over the instrument pod, seats and roll hoops (non roll hoop version available). It seemed pretty secure but I wanted to put this thing to the test. I got out my $30 Sears electric leaf blower and and decided to give it a wind tunnel test, at the same time I was curious to see what the motion sensor on my Clifford car alarm would think of a fluttering tonneau cover. What I found out is that if the cover is properly installed I could not blow it loose. The first time I didn’t get the front tucked in good and was able to get the front of the cover loose but the velcro straps and rear tuck kept the cover in place. Not sure what this says about the motion sensor, but it never went off even the one time the front of the cover came loose.

Needless to say I was pretty impressed with what Carter created, and I knew it was a keeper but I decided to do some additional tests. At the time I got the cover we were in the middle of an extreme heat wave in Texas. Everyday after work it was a race to see how quickly I could drop the convertible top to let off all the heat that had built up in the cabin. For a week I kept a fancy digital thermometer in the car, and every time I parked I would place the additional temperature sensor out side the car in the shade. During that week I found out that on average Carter’s cover kept the interior of the car about 7 degrees cooler than with the top up. I’m sure the color of the tonneau had to do with that (silver vs black) but I suspect the open air made the biggest difference. Carter now makes a version of the cover in black and there is a part of me that wishes I would have ordered the black version, but I’m sure it gets a little hotter.

Removal of the cover is super easy. I just unvelcro the cover from one of the side mirrors and pull, off it comes. A couple of quick folds or more likely just wad it up and shove it into any storage space like the top storage behind the seat (if you have it). I usually shove it in the trunk over the tiny crevice above the power top motor. If you have the trunk organizer it would fit in there as well.

I asked Doug Morgan what he thought of his tonneau cover (he has a black design without the roll hoop pocket), Doug replied

It does keep leaves and dust out very effectively and at least moderate amounts of rain; yes I have tested this out. If you are careful you can even get the water out without getting it on your interior. For those that live in the hotter areas of the country it does a great job of keeping the interior cool. It became an invaluable item on the BAD IV tour to keep the seats from burning your legs when returning from one of the little jaunts (the steering wheel and door edge didn’t burn either). Carter’s tonneau is a must have on the Homecoming Convoy also. The tonneau is make of lightweight water repellant fabric, which makes for great protection without being bulky so it avoids taking up valuable trunk space.

Personally, my only complaint is that it requires the boot cover, without the boot cover it really doesn’t tuck into or get secured in the back. It is still usable but I suspect a strong breeze could blow the back end loose. But considering it is only $78.90 it really is a fantastic cover. I think the fact that it is designed by a BMW Z3 owner tells you that the product is well thought out and functional. I’m very impressed with it and use it quite often, since that initial leaf blower test it has never come loose, and it has still never caused a problem with my car alarm. I guess the motion sensor goes right through the material because the motion sensor still works.

Carter sells the tonneau cover via a web page, and has lots of information about the roadster tonneau at that web site. Carter offers versions designed for Z3s with the BMW roll hoops and for Z3s without the roll hoops. Both versions of the roadster tonneau are available in black and gray. They are made of a strong, lightweight, compact, and water-repellant nylon taffeta. Whichever version and color you choose the total cost including shipping is only $78.90

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