When Q, sla and I were on a roadtrip N years ago (where N > 10), we saw an illinois license plate 'TAXPROF'. We wondered why someone wanted to tax me so badly that he got it on his license plate...
The oddest license plate I've seen was on a trip home to East Millinocket, there was a minivan with the license plate PB4UGO -- good advice, but why put it on a license plate??