All American rally cars, no matter how sophisticated, are street legal. They have to be: The rules require that they be driven on public roads between the competition legs, or stages, of a rally. The competitive stages, meanwhile, take place on byways that are about as far removed as you can get from the ones people normally drive on -- roads so rugged and daunting that you half expect to see a "Danger! Do Not Enter!" sign posted. Blind crests, wicked hairpins, cliffs, trees, water crossings, dirt, gravel, snow, sleet -- this is what rally drivers have to deal with at speeds that sometimes exceed 120 mph. "I think this can be the next (big) extreme sport," says Lauchlin O'Sullivan, a Mitsubishi team driver. "I think it can go all the way."