Mercedes-Benz A-Class
but tightening emissions laws meant that it was launched with an updated Ford Kent engine instead. This was followed by the innovative engineering designs; Mercedes-Benz A-Class with an under floor engine, the two seater rear engined Smart ForTwo, and the aluminium bodied Audi A2 which in its most aerodynamic form only achieved a . Sales really took off with the 2001 BMW Mini with its modern but conventional front wheel drive engineering and re-interpretation of the classic Austin Mini styling. This has sold well in other markets including North America. Other cars of this type include the Mitsubishi Colt-based Smart Forfour, VW Polo based Audi A1, Fiat Panda based Fiat Nuova 500, Citroën C3 based Citroën DS3, and Fiat Grande Punto based Alfa Romeo MiTo. The Toyota iQ, designed in France, went on sale in January 2009 in the UK. It is a competitor for the Smart ForTwo but with occasional rear seats. It follows the Issigonis philosophy of packaging, with innovations including a flat under floor fuel tank and specially located steering rack and final drive unit to maximise floor space for passengers. It seats four adults in a car long, wide, and tall, and achieves with a 99 g/km rating. It also achieved the top Euro NCAP 5/5 stars safety rating.