Hey guys I own a VX S Pack with a fully standard ecotec, Its a first car and I want it too sound decent and backfire/crackle but without it sounding like some thrashed v6 with a chopped exhaust. Ive been looking at videos of the redback 2.5 inch catback and they sound pretty good. But my question was which catback to go with. 2.5 Inch single muffler then straight. 2.5 Inch square muffler than round muffler to twin Pretty much just asking peoples opinions on what will sound better and how loud it will be, Cheers guys.