The Rosso twins are
AO Silver Member
Join Date: Oct 2011
Location: United Kingdom
County: Tyne and Wear
Yes many have, I have removed precat (Js Tuning) and main cat, got a Supersprint centre section(replaces the main cat mated to a Novitec duplex rear box only the rear silencer remaining although some run with no silencer's.
Well worth doing, the spool up is much better and the car much more responsive and gives a nice noise when booted, but not loud when sitting on the motorway.
There are a couple of threads covering it in more detail.