Do you happen to know which 3M adhesive is best? There used to be a 3M Super 77 (or something like that) but I don't see it anymore. Didn't work well anyway.
Seems all I see nowadays is a 3M General Purpose adhesive (claims a medium strength hold) and a super-duper version with hard hold. The hard hold stuff says not to use on some types of foam. I don't know what type of foam headliner is made from.
I think we used to use 3M 90 (or was it 99?) and that worked okay but heat would eventually make it let go.