I'm looking at a CPO 991.2 that appears to have white markings in all of the valleys of the center lock nuts. It isn't wear on the raised portions, so does not appear from being removed many times. Has anyone seen this before? Is there a way to address it without completely stripping and recoating the nuts? Thanks!

 

Buddy of mine pointed this out on mine and said this happened to his car too. It comes from acidic wheel cleaners apparently.

 

Have them replaced. These are wear items especially if car sees track miles.

 

It's from wheel cleaner unfortunately. Moving forward just make sure anyone who washes your car is using soap and water only on the wheels.

 

Cleaners wear them all, although those pictured look worn more than normal. New ones are about $1k per set.