My first time messing around with Cinemachine for the camera effects, and I gotta say I'm pretty impressed with it. I also experimented with a more realistic car controller and... meh. I liked this sloppy burnout mess machine better somehow, at least for this game.
30 seconds is undeniably tough! However, assuming the countdown is starting from the pizza gate, I assure you that each delivery is indeed possible. Some are very tough (I think I speak for everyone when I say "F the Financial District"), but others should be absolutely easily doable, with time to spare, and extra cash to earn.
Earn enough money, and upgrades do unlock over time, improving things like speed and handling. I did consider doing an upgrade shop, you may have noticed the Mechanic's shop still in the game, a holdover from that idea which got repurposed.