I do the print design work for exhaustsUK.com (not the website though).
You can call them on 0800 043 5011, pete jarvis (you can say aaron @ 221 gave you his number) is the one to talk to.
I have read and seen they do cat back systems (not sure for A2) but the quality is very good, as I've had the products on my desk for photography.
Hope this helps.
bba