Career / Campaign based single player mode. I envision something like this. You start the game with a small amount of cash at a used car dealership. It could be a small lot that spawns older cars with varying amounts of damage or missing components. (Maybe make special "parts" like old used engines just for the used cars, lower power and a different sounds like ticking and knocking, maybe add a hesitation.) To make money you should have a few choices. The first choice could be doing deliveries, you go to the local warehouse and enter the building, you get a dialogue with a few runs to chose from to various locations on the map and you get paid for distance. Any impact damage or busted shocks etc would cost you. Another obvious option could be races of various types. Another job could be a tow truck driver if that was implemented.. Another simple one would be a garbage truck. A good entry level race could be a hit to pass, hit the car infront of you before you pass. Small reward, high risk. Maybe rock crawling and hill climb competitions, track racing, rally racing, etc. - Car dealerships. - Delivery jobs and other odd jobs to earn cash at first or if you destroy your car. - Interesting races and competitions such as hit to pass racing and hill climbing competitions. Edit- Speaking of the used parts, maybe to repair your cars at first, or for hit to pass or cheap beater wagons you could buy used parts that are randomly worn or have random characteristics.
I've pretty much has this exact idea myself. It's like a better version of MotorM4X with a broader variety of "missions" and vehicles
Races would be an excellent feature, just thinking about racing around a cliff driving next to another driver and pushing that vehicle off the cliff. XD
The delivery jobs gave me a nice idea: like EuroTruckSim/18WoS where you can have a company and you do deliveries, but you could do other jobs other than deliveries and not just using trucks, for example, towing a car with a tow truck or using the van instead for deliveries. (I'm gonna make that if you don't )