It's a game that I have to play to finish.. good job
I think you may have touched on something. Sometimes it's better to go with a car than the very souped up bus. maybe think of the vehicles vs the track as rock paper scissors.
once again, good job.

Likes: smooth controls, good music, nice graphics, variety of tracks (some climbing, some flatter)

Dislikes: money system seems arbitrary - is it somehow related to where you finish in the race? Getting 1st or coming 5th don't seem to make much difference. Money buys all upgrades quite quickly. Before taking a level we don't get a preview map, or at least a summary to what kind of level it is (e.g. technical or flat); the truck is very good at flat courses but the cars are good for the technical courses. As such it would be good to be able to select a car from your garage that is most suitable for the upcoming level. Also, it should be possible to go back to the garage and select a different car when you restart a level, if you find your original vehicle choice is unsuitable.

Wait what? I was going to play like first two levels and then quit but I accidentally went through the whole game, what?! This game is so friggin' good! Like after purchasing all the upgrades for the car I played with the money system was kinda boring, but still! Awesome game!

ok, i played through the whole damn thing, so you did good.
graphics, music and artwork are all well executed.
the tecnical parts also seems to be very good. no lag, short loadtime, good controls.
this kind of game is nothing new to me or the internet so at this point i'd give 4/5 (because with a concept that has been around for so long, 5 points are just out of reach)

but:
the upgrades feel kinda off. you get so much money for the first completion of a level that your position doesnt matter at all...
and the best vehicle is the supply truck. really? thats anticlimatic
also, you advertised you game as "fast paced" when in reality most of the tracks are rather slow climbing courses... (i actually got a little exited when i read "fast paced")

This is the best car game I ever played! I like the way you have to press arrow keys to turn back over and how challenging it is.