My wife normally takes on the naming of the cars
'03 Cobra (his): "Elwood"
'03 Miata (hers): "Jake"
(Hint: they're both blue)
'00 Focus: "Frosty (the snow car)" It's white and used when it snows.
'03 S10: "Buttons" (after Comedian Red Buttons) it's red
'96 Taurus: "The golf ball" (salvaged hail car--it's white, round and full of dimples)
I don't have a name for my car, but my old girlfriend and her best friend call my car Pinky. They were riding around with me one time and asked if I had a name for my car and when I said no they're just like, "Well.... your car is now named Pinky." Apparently my ex-girlfriends friend's favorite color is pink or something, I don't know. Its pretty funny though, cause they giggle like hell whenever they refer my car by that name...