Cat back exhausts

Having trouble finding any second hand exhausts for my a3 1.8 TFSI Sportback so I am wondering... will any catback fit? What I mean is as long as it is a designed for a sportback will the 2.0 TFSI and even 3.2 FSI Catbacks fit my car? I am guessing they all route the same and I could probably get an adaptor for the downpipe if it is a different diameter!?

Thx

Does anyone have a schematic for the exhaust system on the 8P2 Sportback 1.8t FSI?

Having had a think and only really wanting some extra noise I am thinking of either taking the centre pipe out, gutting it and fitting it back again or cutting the backbox out and have someone weld some pipe in between and leaving the centre silencer in. Was driving my car earlier in between some concrete walls and all I could hear was the whining sound all FSI engines make... no exhaust boom at all