Do you have bumper stickers, license plate holders, any other decoration of your car that ID your genre affiliations?
I have a friend that had "Republicans for Voldemort" bumper stickers who got an irrational amount of guff for being Conservative. This is a price you pay.
I considered a custom license plate (ordered it even, but never picked it up) that was both nerdy and had my real name in it (above friend had her 'nym shouted out on Buffy and it's her plate, she made me jealous), but chickened out majorly. Bad me.
(That's my license plate holder, BTW. I Cafepressed it because I had a NEED).