thanks everyone. to answer avfrog's question, not too loud inside. when i first did this set-up i asked my wife if it was to loud for her (she doesn't care a thing about trucks) and she replied "sounds good to me" in which i was shocked! it seems docile while driving and not too bad when floored as my 2 year old makes vvvrroomm sounds when i hit the gas. when i had no cats it was not cool but now much less than a truck with straights.