I would personally love it if it ended up that way, and as I said before if people don't wanna build / tune the car up themselves they could send it to a mechanic to have it tuned there for an extra fee.

I like the idea of having the car tuning similar to Car Mechanic Simulator, and if people don't want to go through all the work they could simply send it to a mechanic to get the car tuned there, for an extra fee ofcourse.