For the career mode type thing, there should be an in-depth cuztomization. Like, REALLY in depth.
For example:
1: Choose what chassis you wanna use
Examples:
Cohen
CRD
Willman
PEI
2: Chose what kind of body you wanna use
This one I think is the most in-depth. You can choose any type of body you want, like a dump truck, school bus, semi truck, the list goes on.
Heck, you can make your own bodies.
3: Paint schemes
Path of Destruction almost had this one nailed. The only difference is that you can actually put your trucks name on the truck. You couldn't do that with the custom trucks in PoD.