Mine are pitted unfortunately. I got the car with 12k on the clocks and the tips were ruined. Audi wouldn’t cover them under their warranty unfortunately and it’s £130 or so to replace them
Certainly is available in the UK. Might steal the wifes as she uses it for things like the stainless steel sink occasionally.This is the go to product for exhaust tip cleaning in Oz by most... unsure if available globally.
http://www.barkeepersfriend.com.au/bar-keepers-friend-cleanser-polish-powder-340g