The current curve is just a temporary system to check out if people like it or not. Apparently you don't as it is right now. Your opinion will count to the next "system". :)
Also: It seems to easy to get your car to level 5 to smoke the other racers. It only took me 3-4 races to get level 5 and I now come in first without even using boost.
This reminds me of F1 racer for the Original Gameboy. Plays pretty good so far. Playing around with the changes to the engine, handling and boost, Maxing engine and boost with 0% boost seemed to work the best. I also agree with Superconnor. I demand purple car!
The current curve is just a temporary system to check out if people like it or not. Apparently you don't as it is right now. Your opinion will count to the next "system". :)