Just driving...
I liked some of the art that you had in the flash. Im guessing you spent a good deal of time on the cars.
However it seemed to be there were some graphical glitches in the flash... at all times there was empty white space above and below the main image... Normally I wouldn't bring that up, but you had the cars moving in that white space... you should have filled it in with scenary or detail. And there was one point in the film where the blue car seemed to rear-end the black car but nothing happened...
Music and sound effects were good enough
But the story was lacking... as I said, all it had was a couple people driving around in nice looking cars. I guess that's a story in itself, but I'm left wondering WHY? Was one guy chasing the other? Is one guy trying to kill the other? Or are they just simply racing? What's going on? These are things you should try to address.
Keep at it though.