Just seen this on ebay and thought it might be of use to someone on here building a new car - NTDWM but looks like a good price for an exhaust and CAT, good quality too.

http://cgi.ebay.co.uk/dax-rush-exhaust-kitcar-kit-car-silencer-with-catalyst_W0QQitemZ270194529344QQihZ017QQcategoryZ38786QQssPageNameZWDVWQQrdZ1QQcmd ZViewItem

Cheers Mike