Tod's has done a great job of inventing a myth here. Real race drivers never wear these rubber-nub things-- and in fact non tie-up shoes are prohibited at most performance driving schools. The last time I saw Hurley Haywood at a track teaching, he had on plain 'ol white sneakers. On race day professional racing drivers wear Nomex-lined suede ankle boots with thin, rock-climbing type rubber soles, as required by competition regulations.
The real keys to good driving shoes are that the sole isn't too wide or too thick or too slippery. Too wide, and it gets in the way of your pedal work, because on a properly set up car, the pedals are quite close together, and shoes with wide soles tend to get hung up on the wrong pedals. A thin sole is also nice, as it gives you a better feel for the pedals. The sole should also be made of a sticky rubber compound (or dots) so as to give a good grip on the pedals. I have some Tods-like driving shoes. They work fine for casual "spririted" driving. I wouldn't pay a whole lot of money for driving mocs, however, (Tods prices are ridiculous) as these shoes aren't really built to last a long time. The rubber nubs wear out really quickly if you do much walking in them at all. Unlike a good pair of dress shoes, I view my driving mocs as somewhat short-lived, and gauge the price I'm willing to pay accordingly. Land's End has driving mocs that are very nice and quite cheap. If you want some more durable driving shoes, you may want to check out shoed by Piloti. They are more "sneaker-like" than Tods, but are built to last a bit longer. www.piloti.com
I have a couple pairs of Pilotis, and find them a nice mix of function for driving, walking comfort, and durability.