June 27, 2001
By: Richard Carlson

This article reviews the Z3 Solution alternative to the free BMW window blanket. The Z3 Solution product has been designed to minimize or eliminate the dreaded "wave" whcih forms when you leave the top down on your Z3. It does this by providing extra padding in critical areas. The blanket sells for $37.95 from Z3 Solution.

I'll preface this article with a couple of comments:

• If you are leasing your Z3 and you plan on turning it back in, this article is probably not for you.
• If you plan on keeping your Z3 for a couple of years and are worried about it looking good, especially for resale, this is one of the products you should seriously consider.

The picture above shows two window-blankets. The one of the top is the Z3 Solution version, The one on the bottom is the standard BMW version. They are both made of just about the same type of flannel material, the BMW version is gray, the Z3 Solution version is beige. You can see from the picture that the Z3 Solution version is a bit smaller than the BMW version. There is one critical difference between the two of them: The blanket on the top can prevent the dreaded "wave" in the Z3 plastic windows.

Get stuffed!
The wave is the effect you see when you put your top down for an extended period of time. When you put the roof back up there is a slight wave which goes horizontally across the window. It's caused by one of the roof supports hitting the window and creating pressure. Since the Z3 first came out, people have been trying to get rid of the wave by stuffing various things into the fold of the roof. There used to be round pillows you could buy and many people also used pipe insullation material in an attempt to get rid of the wave. None of these approaches worked very well.

Keith, of Z3 Solution, studied the folding of his roof and determined that many of the earlier attempts to combat the wave were really addressing the wrong part of the window. The actual culprit is not the place where the window folds, instead he determined that the second support from the back actually rubs along the window with a lot of pressure creating both the wave and the associated scratch marks.

Holding up the roof
Keith determined that some padding in the window blanket would be the perfect way to protect the window from the damage caused by the roof support. The problem was that padding the whole thing would mean that the blanket would be bulky in areas where the bulk wasn't needed. The first think Keith did was to cut down the size of the blanket to just the critical window area. In this way the padded blanket places no extra strain on the roof which might lead to premature wear. The next thing was to pad only the lower two thirds of the blanket, eliminating the bulk at the critical bend in the window.

BMW Quality
Keith was also concerned about the quality of the unit. He tested out various materials to simulate the BMW quality. The result is a product which might have come from BMW. Keith uses the same quality fabric, the same connectors and the same quality of fit and finish as the BMW unit. The only obvious difference is the longer loops on the BMW I mentioned that the longer loops and slightly shorter elastics on the BMW model do make it easier to handle and Keith said he would look into addressing this in production versions of the blanket. I have a '97 2.8 with a hard top. In the fall I had the soft-top completely replaced by BMW, so I got a new window. The window has spent the winter crushed under the hard top, so when I took the top off for the spring I had a significant wave. Keith told me that the Z3 Solution blanket will not remove the wave, but it would keep newer cars from acquiring one. Based on experience, I have found if you hit the window with a hairdryer it will straighten out the plastic.

In several weeks of use, the blanket has practically eliminated the wave from my window. I'm very impressed and would recommend this highly to anyone who intends on keeping their car for a while. Using the Z3 Solution window blanket will definately prolong the life of your rear window and give you a much clearer view. With window replacement running anywhere from $150 and up, the $37.95 Z3 Solution Blanket seems like cheap insurance against a hefty repair bill.

Feel free to email me if you have any questions.