This week on The Best of Car Talk, Reid wants to save his Audi's transmission by flushing it, but his mechanic thinks the gunk is the only thing keeping the tranny from self-destructing. Will Tom and Ray embrace the debris theory? Elsewhere, Colleen's dad used the "break brake-in' theory" to insist he had to drive the family to the movies. Was this science or just a way to tell Colleen he thinks she's a stinko driver. Also, Melissa is relying on a rope to keep her driver's door shut; Katie wants to use white gas that's too old for her camp stove in her Corolla; and Tommy pulls out one of his most ingenious ideas to help David get away with buying only two snow tires instead of four. Of course, David may not make it through winter, but does that make it any less brilliant? All this and more, this week on The Best of Car Talk.