I have just had a custom built exhaust fitted by ASCAR Exhaust Ltd in Sheffield. It's thier own make called Cobra Sport. It is fully stainless steel from the CAT back Japanese stlye 4 inch slash cut tail pipe.
It sounds sweet and very loud , it cost £310 fully fitted.
it sound very nice and it's pretty loud but not that kind of loud that gives you a head ache after 2 miles. When you on 5th gear on a the moterway you dont really notice it as much if you know what I mean.