Hi Nick, please can you post a link to the thread that you have found on this.
My 2018 B9 RS4 has the sports exhaust. The black paint on the inside was flaking off and Audi replaced the tips under warranty. They are welded but can be replaced.
The outside is black chrome and I haven’t had any problems with this.
I wash them with soapy water when I wash the car and every few months give them a proper clean.
I use Auto Smart “Tardis” to remove tar and rubber deposits that stick to them, then polish with Autoglym followed by a coat of Poorboys wheel protection to help stop the **** sticking to them. I also apply Poorboys to my red brake callipers and believe they stay cleaner for longer.
However it would be nice to know what others have found to work.
By the way, I was spraying ACF50 into my exhausts to prevent the valves from sticking which has happened before. This may have caused the flaking mat paint inside my exhausts, so I don’t clean inside anymore or spray anything. I do grease the shafts top and bottom from time to time.
Cheers Paul
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