Contact Cement
WARNING: This page does not describe the selected car, but rather 257 other vehicles, including the 2006 BMW Z4, 2006 BMW X5, 2006 BMW X3, 2006 BMW M6, and 2006 BMW M5. However, it is still accessible from the selected car via links, so may be relevant.
Attaching soft top material to zip-out rear window trim plastic channel on E30 and E36 convertibles. (former BMW Part No. 81 22 9 407 524)
3M 1357 High Performance Contact Adhesive
See S.I. Bulletin B 54 01 93 (3754).