Dan...........i ve had ceramic coating done on a 4 into 1 exhaust system........and i was very impressed with the result.
From memory it was nt too expensive........and keeps its looks very well over the years.
The process was explained to me at the time with the advantage that it coated both outside and inside at the same time.
I would nt hesitate to recommend this as a finish for the outside as well .........as it is an enduring coating.
