A state trooper pulls a car over on a lonely back road and approaches the driver. "Sir, is there a reason that you're weaving all over the road?" The driver replied, "Oh officer, thank goodness you're here! I almost had an accident! I looked up and suddenly saw there was a tree right in front of me! I swerved to the left and wouldn't you know it, there was another tree in front of me. I swerved to the right and there was still another one, again right in front of me!" The officer leaned into his window, reached to his rear-view mirror and pulled off the item hanging from it. "Sir," he says patiently, "that was your air freshener."