This week on The Best of Car Talk, is "Backseat Driver Syndrome" incurable? Lani got used to yelling at her husband when he was a stinko driver, but now that he’s doing better behind the wheel, she’s still nagging from the passenger seat. Old habits die hard, it seems. Meanwhile, Christine is wondering if she needs to give up knitting in the passenger seat, lest a deploying airbag turn her needles into projectiles. Also, Jem needs to clean a stuck valve, but the gunk may be the only thing holding his engine together; Matthew’s struggles to start his Jetta are giving his neighbor’s lots of laughs; and even after three alignments, Russ still thinks his car may be headed for a ditch. All this and more, this week on The Best of Car Talk.