I have searched already and found only one thread about this. I have the Borla Stinger cat-back and my tips have build-up on them and will not come off!! I have tried mothers, eagle one, never-dull, the rolled edge is all black too and its buggin the hell out of me, i want them to shine like they did when i bought them. ANY suggestions>?? Any at all??? Help me out guys. :shrug: