Hey gang,
I still own sprayed on truck bedliner equipment. I operated a few franchise locations.
One thing that we did for retail trucks, was place a UV top coat over the spray liner called Restorez. It was a product made by my vendor that was not an activated product (it air drys) but it was specifically made to bond to sun dried plastics and ploymers. I did a CJ hard top with it 4 years ago, a double coat, first coat then a light scuff with a green dish scrubber, and then a second coat. I sold the jeep to a friend, and the top still looks great. The product that I would regularly use was a gloss black product that made worn spray bedliner or new bedliners in retail trucks shine really nice. It was not exactly OEM finish but they do make a dull variation of this product.
If this was to be packaged into a bottle, called Hard Top Restorz for Jeeps (in enough to put to generous coats on a regular top/with enough left over to do a long wheel base top) How much would you be willing to pay for this??