Don't forget that the changes may adjust back pressure and tune. I have always used the rule that a significant adjustment to the exhaust should be linked with a rolling road ECU map to optimise them.
I have a plan to tune the engine in our family car now it is out of warranty but plan to change the exhaust first and then put it through a map change.
If you are looking for a custom exhaust fabricator give these guys a call and ask for the name of nearby company they use ?
www.mslperformance.co.uk (assumes you maybe be near Brum)
