I asked a former police officer lately what the police think of radar detectors. His opinion was that he didn't mind them, and that most officers don't either. Of course, he qualified this opinion by suggesting that a detector may help someone to be more observant of the speed limits. I agree. Combine that logic with the assumption that the M3 is easy to drive fast, and is also generally safer at high speed than most other cars (I said "generally"), and I'd say you have a pretty good lesson to impart.