Here's some more information from the survey, listing the ten best and worst makes & models:
Warranty Direct’s top ten models over three years old in terms of average warranty repair cost were in descending order the Ford Ka, VW Polo, Volvo S/V40, Renault Clio, Mazda MX-5, Vauxhall Corsa, Vauxhall Astra, Ford Focus, Ford Mondeo, and Volvo 850. The Mazda had the fewest claims per 100 Warranty Direct policies, at 8%.
Warranty Direct’s bottom ten models in descending order of average warranty repair cost were the Subaru Impreza, Jeep Cherokee, Porsche Boxster, Range Rover, Ford Scorpio, Fiat Coupe, Saab 9000, Mitsubishi Shogun, Rover 600, and Nissan Primera. Of these, the now-discountinued Ford Scorpio had the highest incidence of warranty claims, at 55% of Warranty direct policies on the vehicle.