[JimD]

You might try one of the stronger solvents - like goo off. I think I used goo gone or something like that - I bought it at Walmart. When you wipe the visor with it you get a little black on the cloth or paper towel. So it is disolving the visor a little. I had no outline of the sticker when I was done and the visors look good. At first they seemed to have expanded a little where the solvent was on them but they shrank back to the original profile.

Jim