Crying works too.
Our daughter was stopped for speeding.
She started crying, and crying, and crying.
The officer told her to take it easy, calm down...then he let her go without a ticket.
Of course, she displayed simple courtesy and politeness too.
Wave the cop in real close, and whisper "she's having really bad 'female problems', and she needs to see her OBGYN".
The cop will always be too embarrassed to follow up for fear of showing his ignorance, and he'll just let the guy go.