I really like the vibe of your game but execution had major problems.
You made the controls hard and confusing for no reason. Why not make engine just start with E? Space is nearly in all car games are the brakes why use space+mouse when you can just use mouse? UI was also not helping, I found out we have a mirror after 3-4 run. AI was hitting me even before game starts and was very hard to doge.
The most major problem was the car movement was not like a car but some rectangle on a ice. Now you could still use this to your advantage if you make the theme on an icy road where also the AI cars were affected. This would fix the narrative (like why the cars are hitting me) and make the car movement more believable. With a real traffic where some cars are slower and some faster it would be fun even trying to reach the end. I would also hide how much cargo you lost from UI and put the scale part at the end of the game where it also shows your score.
If this game was more user friendly I would play this until finished all the upgrades for sure.