Exhaust valves

[roasty]

Right so my current setup is just a invidia cat back on standard cats and I like the sound for motorway driving but round town just dosn't quite live up to expectation so my question is has anybody fitted a butterfly valve kit to there exhaust and what kits are available any help would be greatly appreciated

[MikeyM]

Be interesting to hear of any results... I was lookibg for these as well