This week on The Best of Car Talk, genetics suggest that men inherit intelligence from their mothers, which as Tom and Ray postulate, leaves one likely source for the "Hey guys, watch this!" gene. And to prove that point, Josh in Montana is testing the theory by trying to find the source of his truck's rattling noise by examining the under carriage—while the truck is moving. Also, Sara can't figure out how her pet chicken survived a ride under the hood of her Tahoe; John the mechanic needs to know the labor rate for evil ex-girlfriends; Cathy's Sentra is sending her to the poor house; and on Stump the Chumps, we find out if Michael fixed his father-on-law's Town Car and inherited it in the process. All this and more, this week on The Best of Car Talk.