Car Coins

Right now you can't do anything with them, other than collect them (and Man, I have quite a collection!!!). You are awarded coins based on how you finish in a race. You get more for finishing first, and you get more for finishing on a harder level.

Training track - You get nothing but experience

Carburator County Speedway and Twisten Tailfin Track

Easy
no matter how you finish - 1 coin

Medium
First - 2 coins
Second - 1 coin
Third - 1 coin
Last - 1 coin

Hard
First - 4 coins
Second -3 coins
Third - 2 coins
Last - 1 coin

You also seem to get a bonus for having atleast the alltime fast time for the track and that level- 5 coins. I saw it for the first time today on TTT where I got 9 coins. Later while playing on Easy (I can't stand the easy level) I got 6 for the race that gave me the fast time for the track. A nice little bonus.

When the game first opened there was a catalog where you can spend the coins to upgrade/style your car. I assume that they will bring this back once they go live. Unsure if any of the upgrades would actually change the handling/speed of the car.