After searching this site and a few others, I could not find the answer to this. I have an 03 GT vert and I just bought some Mac longtubes and I'm looking into an H-pipe. I have already ordered a Mac catted shorty H and it is taking forever to get to me since Mac doesn't have any cats as of last week. I really want this exhaust on before my vacation so I'm thinking about going catless. Just talked to a friend who has a catless camaro and he said hes getting black crap, I'm assuming carbon deposits, all over his back seat (coupe). I wanted to know if anyone here is having problems with getting smog in their car or black stuff all over the interior from going catless in a vert.