This week on Car Talk, how big a focus group do you need to declare a car too "dorky"? For Kelsey in Sacramento, the fact that her mom drives a Prius is all the research she needs to consign it to Dorkdom. Meanwhile, Lisa in Michigan is wondering whether a facelift on her Volvo will rekindle her affections enough to keep it running or a few more years, and Colin in Oregon is losing sleep after his wife's oil change misadventures. Also, is a summer in the desert hot enough to melt four tires, and on Stump the Chumps, did the ol' "bad heat shield" diagnosis prove true for Champagne in Miami? All this, plus a new puzzler from the Medieval Castle series, and lots more, this week on Car Talk.