I love the idea ! I'm sure that you can find some nice gameplay ideas to go deeper in the concept ! I had no sound, is that on purpose ? A "good bip" and "bad beep" when clicking a car could be really cool. I got confused by the fact that <90kmh cars' speed is green and red if above because green means "Nice, this was the right car to click" for me but I don't know if others have the same opinion ?
Great work ! :)