This week on The Best of Car Talk, our all-time favorite neurological oddity: a Massachusetts man begins speaking with a French accent following an accident. Could a whack to the noggin make Tom and Ray speak like actual mechanics? Also, three tales of things that aren't where they're supposed to be. John's dipstick keeps popping out, Crystie dropped a nail into her gas tank, and Dana's friend has a piece of the Berlin Wall lodged in his dad's BMW's trunk. And, Julie "backed into a car that wasn't there" and didn't confess to her husband. Is it time to come clean? All this and more, this week on The Best of Car Talk.