I love all those suggestions! I have some ideas for the main gameplay loop too - was thinking of changing it around so that there's an overall timer (or a fixed amount of pavement) and you have to go pick up the cars instead of starting with them. When you get a new car, it has a specific destination assigned and if you can deliver it you get rewarded with something (extra time, or maybe money you can spend on upgrades or more time/pavement).