Nice work, really like the simple aesthetic, looks nice and clean. Concept was pretty neat, though I found myself using it to speed myself up and slow others down rather than speeding other cards up to make them miss.
I think at some point your car should probably just explode. You can reach a point where your car is so slow that you pretty much have to restart because it's impossible to make it in time.
As you said in the description, the collision is quite buggy, I even got pushed through a wall which allowed me to get away from about a hundred police cars.
I feel like whenever I released the time warp on my car, a literal army of cops would come from offscreen and completely surround me. I think if you made the "time return" effect a tad quicker you could actually escape in that scenario.