Super rubber cement
Originally marketed to repair old tennis shoes (which it does very well), this industrial strength rubber cement has many, many purposes.
I had a problem with the trim falling off of my second Mazda Rx-7, so I went around the car and pulled off all the trim and re-glued it with Shoe Goo. I never had the problem again. Through all kinds of weather and at very irresponsible speeds, the trim was still on the car after the vehicle was used up, wrung out, stripped of parts for my third Rx-7 and sold to a salvage yard for scrap metal.
Goop makes several other varieties that are supposedly specialized for different applications, but after trying them I keep going back to the original.01/23/18
(Note: Apparently "Shoe Goo" is not a trademark. Several products from differing manufacturers use the same name, in very similar packaging. Amazing Goop is the brand Justin Belshe used. Beware of imitations! — editors)