i've been caught twice and let away with it twice
1st time was towing car to knockhill, my towcar was full to the brim with cherry, trailer had 2 baldy tyres(i didn't know about these

), and lights not working on trailer, was 7am and snowing heavy, guy just couldn't be bothered and told me to get to fuck, i know how lucky i was, but
2nd time my car was lying outside my work
i worked in bonnybridge at the time which is a haven for red diesel, anyhow
they dipped my tank but couldn't do anything about it as itwas parked in a private car park and not on the public road, was obviously warned that if it was seen on the road it would be stopped and siezed,

anyhow lesson learnt
my 406 work horse has only ever seen red once since i got it and thats cause somebody got a loan of it, i only ever use white now, i'm not tempring fate the 3rd time