Hi Just to add some comments on this subject. In my previous life I owned a C4 Corvette which I heavily modified through John Camilleri at Performance Pipes and Prochargers www.performancepipes.com.au I then had the brock shop do the tuning ( Sham Sham ) Sorry guys. However it was the first time I experianced a negative attitude from a tuner. I understand now that the Brock shop has closed down.... However I can highly recommend John at Performance Pipes at Acacia ridge in Brisvagas. I have owned BA & BF XR6T and now own an FG XR6T Ute and Performance pipes has built and installed dump pipes, high flow cats & exhausts for all of my cars and he is currently building my 4 inch dump, 4 inch 100 cell cat and 3 & half inch single exhaust with megnaflow high flow mufflers and I am getting him to HPC the whole system to reduce drag internally and reduce heat loss externally of the system. Performance pipes has also serviced and built / installed All the usual mods available for the XR6T's. I recommend him based on experiance, Price and most of all Just a great guy with a 20 year experiance in the modified car industry. Just my experiance Guy's Regards XRT60