Automotive Plastics: Rear windshield 3rd Brake Light, tail light, third

Question
Hi Octavio, please could you advice me on which type of adhesive to use to re-attach the black plastic 3rd brake light housing to the rear window of my car?

After replacing the glass I tried with re-installing it with double sided high strength foam tape (black) but after a week or so the light fell off...

Many thanks in advance!

Martin

Answer
Hi Martin, plastic and glass are both low energy materials and difficult to join strongly in the interface. Therefore I would try either lockquick (from loctite. kit of primer and adhesive). this is used as oem in windshield rearview mirrors. Or sikaflex (polyurethane from sika). The later may require to bore minute holes for the adhesive to come thru and provide a mechanical joint and... naturally a good primer, clean surfaces and time to cure.
If you find markings in the plastic as >PMMA< or ABS, I would make use of the former first. Sanding both surfaces with 600 grit helps. Thanks