hey mwellbel, probably a stupid answer but do the cans have a BS or E- mark on them? If so then unless they are ultra loud most police will let you off or worse case give you a vehicle rectification notice to have it checked at an mot station to make sure it is legal, by which time you can get it sorted. I haven't heard a case yet from my friends or local bikers about them getting the fixed penalty on the spot for having a marked exhaust that they have taken the baffles out etc.
If the cans are unmarked then you run the risk of a fixed penalty which is £30 each time you get done. I wouldn't recommend race cans although I'm sure loads of people will tell you not to worry and use race cans anyway.
Also worth taking into consideration is where in the UK are you? In London the met police have actually said they are not bothered by loud exhausts and even if you are stopped it is up to each officers discretion about what action to take, so if you're a smooth talker you should be able to blag it
But some forces are really purging loud exhausts, Derbyshire police are really going at it from what I've heard.
Hope this helped or if not confirmed that I am a total numpty
Alex aka. muppet :twofinger
