I have a 2003 BA XR8 manual sedan and the exhaust on it at the moment isn't loud enough. Don't really know what the car has because the previous owner said "I think it has... .... ..." a lot. Anyway he THINKS it has Di Filipo Headers (anyone know how to tell?). I've had a quick look under the car and it looks like the cats have been straight piped. 2 into 1 cat back.

Looking at making up a twin 3" cat back possibly split over the diff and into quad. Want it to be pretty loud... Not stupid loud, but louder than your average Joe with an aftermarket exhaust. I've been told by a couple of people to use cobys/hotdogs, but where do I put them and how many/what size do I need? Like do I put 1 on each pipe before it splits or should I put 1 on each just before the tail piece? Do I need additional mufflers?

I cut out all mufflers on my old factory 2.25" exhaust and it was loud enough, but sounded like a v6 and had a nasty cackle at a certain rev range. Also droned excessively.

{DESCRIPTION} "(Phantom) Rays XR8 sedan has simular 229rwkw BPT CAI, Pacemaker headers with twin 3' with 3 1/2 over the diff.
at APS tuning day everyone made a comment Best sounding BA."

Maybe 3.5" over the diff?

{DESCRIPTION}

This is pretty much exactly what I want it to sound like.

Any tips/flaws/comments appreciated!

Oh also what thickness pipe should I use? 1.6mm or 2mm? Or won't make any difference?