Other manufacturers had no production four-wheel drive car on which to base their response, so FISA was persuaded to change the rules, and open the Championship to cars in Group B. This allowed cars to be much further removed from production models, and so was created a generation of rallying supercars, of which the most radical and impressive were the Peugeot 205 T16, Renault 5 Turbo and the Lancia Delta S4, with flimsy fibreglass bodies roughly the shape of the standard car tacked onto lightweight spaceframe chassis, four-wheel drive, and power outputs reportedly as high as 600 horsepower .