This time up, it's the Audi A1 - in our test the Ambition S Line edition with a top-line 1.4 liter TFSI engine delivering 136 kW. It’s up against the Cooper S with 135 kW from a 1.6 liter gasoline unit with a twin-scroll turbocharger. Both models are aimed at younger drivers who are willing to spend a little extra for a small car.