I have an 87 745 with a cracked windshield, and two good used windshields to choose from, both of which are already out of the car and cleaned of old sealant. As I was the one who removed them from parts cars, I think I can handle the procedure of installing one of them in my car (getting the old one out, is obviously, not a problem) but I have a couple of questions, primarily concerning the adhesive to use. I have read that the original material is butyl, and have obtained some 3M Butyl tape, but then I read the FAQ section of this site in which someone (working on a 240, incidentally) recommends using urethane instead. My concern with this is that it might make it very difficult to remove the glass should it become necessary to replace it again. If the butyl tape is suitable, should all the old material be removed from the pinch weld area in which the glass seats, or will the new adhere to the old satisfactorily. Is any sort of primer or activator needed, or just put the glass in place and gently, gradually press it down? What about temeperature? I imagine it would work better in warmer conditions.

I would appreciate any advice from anyone who has done a 7 series windshield.

Thanks in advance