Much room for improvement.
I'll try to go through everything that was wrong with this game, without being too harsh.
This game is only 3 race tracks of time attack mode; there's only one player, no AI, and no incentive to play except to beat your own time.
The tracks themselves are designed very poorly. It seems as if you simply took a large grey brush with a thick white outline and drew one on top of a blue background. Nothing more. No scenery, no textures, nothing. Just a grey road in an endless blue sea.
Graphics aside, the tracks don't even take into account that the car doesn't turn at those angles. I found myself constantly having to stop, turn for 4 seconds, and then go again at the multiple sharp turns native to every track.
The racing mechanics were awful. All I can pride you on is the acceleration of the vehicle. Steering mechanics were absolutely dreadful. In fact, they were more "turning mechanics" than steering ones. Cars shouldn't turn when static (the tires don't even rotate). One more thing I noticed was that when going in reverse and turning, the direction the car steered in changed (while I was holding the same keys).
On that note, race cars don't reverse nearly as fast as they accelerate, a fact which you neglected.
As for lap completion, I started cutting through the track in the first level, and it would randomly declare me as having gone on to the next lap. Halfway through my 3rd lap it congratulated me on finishing and went to the "submit score" page.
And on that note, I find the whole MochiAds thing to be extremely irritating. I was surprised it wouldn't randomly mid-race go to a time-out and then show me a new advertisement. Even if the game was half-decent I wouldn't stand for that much advertisement, let alone for this.
Overall, I find that this 'fun racing game' would be something out of a "flash games for first-timers" book, closer to the first few chapters. There have been other racing games on Newgrounds before, and I feel that those should have set some sort of standard.
I'm sure you noticed the flaws in your game and concluded that the game was playable and decided to submit it. Yes, the game is playable, to some extent. However, it's extremely pointless, devoid of any action, and overall poor.
Maybe you should improve on the concept and resubmit a new version, starting with some textured terrain. Best of luck in future submissions, but this one was not a success.