its not '3m double side tape'
it's a product made by 3m designed specifically to hold trim on cars.
it's in most automotive stores.
it works.
but, you can get steel brackets:
they are at hardware stores. come is various sizes.
another pic.
the trick is to jb weld the bolt on the back so you can take it on and off.
See this pic for a similar idea. I used plastic blots. they also come in various sizes.
use polycarbaronate 1/16 thick. Acrylic is to brittle (imho)