While helping a friend remove his cracked and moldy Diamond Shield, we tried almost every chemical on the market including stuff from auto body supply shops. One that did work was "Wyricks sticky substance Remover" that would dissolve the surface of the adhesive that could then be scraped off with plastic putty knife. This process took 5 or 6 applications which took a lot of the chemical and time. So back to Lowes and talked to a women in the paint dept. who said she removed the pallet racking labels. She took me down to the air freshener sprays and handed me a bottle of "Orange Squeeze" air freshener from a company called California Scents. I said I didn't to freshen the air but to remove adhesive thinking she misunderstood my question. She said they use it all the time, that it's 100 per cent citrus extract and works. So for $3.50 what the heck if it doesn't work put it in the bathroom. Well I sprayed it on a 1 ft. square area waited about a minute and scraped it off, amazingly with 2 applications all the adhesive was gone.
Recommended it to another friend and he couldn't believe the results either. Also works well for bottle labels. But I found its safe on clear coat paint but not all plastics as it will melt some plastics so try an small area first. PM me if you have any questions.
Blessings; kdk