If you had a Cat back put on as you said in another thread ur car may also be missing the centre section so you may need everything from the catalytic converter to the back box replaced. The previous owner may of changed the pipe to 2.5 inches, I'm not 100% but you may not be able to connect the two pipes. If you want it quite as a mouse where all you can hear at 5k is the belt whine, then its a new Renault exhaust system you want. However if you want the nice raspy sound and none of the boy racer imagery then get a ktec stealth.