Here is an example, this is the trunk on my Gran Sport. It was all painted, and aligned,but with the new rubber it didn't fit as well and was sticking up a bit. I put a 1/32" shim (used in wheel alignments) painted red so it doesn't sand out much and made the lid fit perfect, I mean PERFECT, it is literally not the thickness of the paint off, it is flawless in height.
The car is FULL of shims, there were piles of shims on these cars, what's one more 1/32 one?
Just how I see it.