Brit Plays Musical Chairs ... In Her Car

9/19/2007 11:11 AM PDT
Britney Spears is fun y'all -- popping in and out of her car while it was stopped at a red light.

Acting like a high schooler who just got her license, Spears and an unknown buddy decided to swap places not once, but twice, as photogs snapped away. Who knew she had "friends" other than Alli?

When the light turned green, Brit was in the driver's seat and drove off.