Very well done incremental game. The game play feels quite polished and it's exciting to build the track and get new cars. The save system, playing while not in active window and audio sliders are a big plus!
If I had to nitpick it would be the clicker part of this game. I'm okay with clicking to boost (although it could be bound to SPACE/ENTER/E/F additionally) because you can upgrade the boost which feels rewarding regarding having to click less. But the prestige mechanic is a bit much clicking to me. I feel like adding an Auto Upgrade Button when unlocking the prestige option would be cool. For the car selected, on click, the Auto Upgrade Button could spend all the money available for the prestige-relevant properties (all but trophy) at once. Meaning if the money was sufficient the next prestige level can be unlocked after 1 click.
I had a lot of fun playing your game, well done!