The rear window on my 1995 e34 was recently shattered, I purchased a used rear window online and installed it, no problems. The seller covered the interior of the window with sticky tape that left residue all over the surface. The defroster strips lay on the surface of the glass, what can I use to clean the crud off the glass without damaging the defroster strips? I've searched several sites to no avail, any input will be appreciated. Thanks!