I've had several vanity plates and haven't had an issue. For the M5 I have "PFFT AMG" coming. My car friends (several of whom drive AMG cars) get a kick out of it, partly because we make fun of some of the slightly less intelligent/sensible idiots who drive them and always want to street race.
I guess it just depends on where you are.
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2014 X5 xDrive50i M Sport Alpine White/Mocha - M Performance, Euro Tail Lights, Traffic Jam Assist, 6WB, and more...
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