One reason is that the actual Flash minigame game is fun. We've played it three times and finally earned our free DLC, which is a free Mercedes-Benz SLR McLaren for Gran Turismo PSP; gotta catch 'em all right? Secondly, is the fact that, like we just mentioned, you get free DLC from performing well in the minigame.
The eight stages have you identifying engine sounds, controlling a car around a track, constructing a road and identifying engine sounds. Awesome.
Upon earning a score of roughly 2,000, your email account will bulge with the download code for your newly claimed Gran Turismo PSP vehicle.