Sadly this is quite buggy.
Cars and powers from the shop don't reliably go away when the run starts, powers that are stated to affect 1 car affect all and anything that copies a car crashes the game.
The concept could be fun and I see where you were going with this but it looks like you just needed more time.
The only thing I actually found was intentionally bad design was having to sit through 59 seconds of animation after the goal is instantly met.