single exhaust on B7
 

OK I am a newb to Audi's but I juse wanted to know could a single exhaust be done instead of a dual like the B7's are? and if so I'm not sure but aren't the B5's?? single exhaust and would their rear bumpers fit or is there a lip kit out there that would allow me to just do a custom single outlet exhaust? and if so would it be ok to run 3" all the way back??