I wouldn't be too worried. I've read in Evo magazine about a guy who had a decat on his Evo irronically and VOSA caught him and gave him 14 days to remove it and go to an MOT centre for an emissions test.
Also if you see any vosa people just take it very easy and try to keep the car as quiet as possible, not saying you definately won't get pulled but certainly better than revving it up to 7000rpm as you go past.[/quote]
Yeah have done that this past week everytime I have seen then, put the car into a high gear and drove past quietly (as you can in a bright yellow car with a yozza).
living near the hole that is London = fail
countryside rules!