I had a similar problem with the wheels on my 88 IROC. Dont bother trying to sand it down. The stuff is tough as nails. I talked to a GOOD paint and body supply shop and they said there isnt much you can do. They said that if you do manage to sand it down a different clear probably wont apply properly and it will just flake off from stone ships. You can buy brand new wheels for a little over 200 a piece. I had to buy one since I had a miss matched wheel. The wheels are worth the money if you want a perfect car!