This week on Car Talk, Marc in New Hampshire learns what catastrophes await when you, A) buy a 100 dollar Peugeot, and B) pay a mechanic in advance. Can Tom and Ray help him get his car back? Or, can they at least stop laughing at him? Meanwhile, chemistry class is in session for John in Ohio, and today's lesson involves his van's radiator, and a certain co-host's dubious "hungry water theory". Elsewhere, Julia is worried that her Dad's obsession with putting a new engine in his Suburban may be causing marital strife; Carla's Accord is making a screech that's scaring her entire neighborhood; and Ariel wants to know how to prepare herself for her first trip to a new car dealer--maybe start with a suit of armor? All this, plus proof that Car Talk can aid physical fitness, and lots more,this week on Car Talk.