JP Exhaust or Top Gear Bredbury?

[KungFuPanda]

I've recently bought a 2006 Audi S6 avant. V10 engine but it's a little muted at the moment. I had a saloon previously and had a Milltek non res fitted. This cost me £1150. I don't want to spend that much this time around although I do want a better sound.

I'm looking at just getting different backboxes with new tips. Does anyone have any experience of either place? JP Exhausts are in Macclesfield. Top Gear are a LongLife exhaust dealer based in Bredbury.