While the early game was quite fun, it does start to drag and have some issues.
The fact that your work queue is shorter than all the parts on a single car (at least the later ones) is rather annoying. Then the fact that you cannot automate that part of the game at all is also not great. While the workers slowly making money is nice, personally I think hiring a worker should let you assign on to a car and they (more slowly) inspect and disassemble the car.
The only other thing is that the XP / whatever to achieve level 9+ is REALLY slow.