Under the exhaust wrapping I got some very nice black corrosion on my M3W.
Like matt paintig.
I did prefer that to the original shiny exhausts. I think wrapped exhausts look good too.

The exhaust after de-wrapping past driving a few 1000 km:
[Linked Image]




Hannes
once: Green M3W; 2013
now: Red 4/4 Sport; 2011
and some practical cars for use in real life