My 2c, I am a bit reluctant to express it but fuck the sensitive types. I had my stainless system ceramic coated internally and externally about 15 years back. That's a set of big bore headers, I forget the dia but they are a bit bigger than std, a 50mm Jota connector and a pair of straight-through Stainless mufflers. I chose their bright finish, which is similar to polished stainless steel. I wanted to avoid that rainbow effect you can get on uncoated exhausts. It's also supposed to be a performance improver. It apparently holds the heat inside the pipe sending it away better down the system, in the car work it reduces under bonnet temps and reduces the chance of burning you. So for the 1st 3 or 4 years, all it needed was a wash to look great, After that it slowly lost its shine needing a rub with Autosol once a year, but lately, it has now become a dull grey. Another thing is Stainless exhausts are notorious for cracking, mine never has. Maybe it's been helped by this heat shedding, who knows? All in all, it was well worth the cost.