Wow! I haven't delved much into 3D game dev, but the city you created was incredibly polished. The main mechanic of the game also worked perfectly. Even after I... may have accidentally mowed a passenger down he still wanted to give me his fare AS LONG as I was within the circle haha.
If I had something to suggest it's like others have said.
The car mass feels like a feather at high speeds. On a long straight way it feels like you'll get slightly airborne and rip to the left or right.
Also some way to have the direction indicator always be showing would be nice.
Some sort of game over and restart after running out of gas. I actually got lucky my first time I ran out and after some mindless drifting about I ran into a gas container! But it was a short-lived victory.
Great jam submission, well done. Cheers!