I bought after-market rims for my M3. They have 10 lug holes to fit two different lug patterns. I would like to plug the extra holes and paint the plugs to match the rims. Any suggestions on what material to use for the plug that will bond well to the rim and handle the expansion/contraction as the wheels heat/cool during use? (One Autozone store owner recommended not using Bondo for this but thought paintable silicone window caulking might work). I'd like the result to be as smooth and unnoticable as possible.