I just checked out this new feature today... sorry if this is digging up old material, but I think the new campaign mode/story missions where you drive around in your pickup truck helping your friends and racing geezers is a super deluxe new feature. It's really fun, and the little cartoon cutscenes are actually really interesting and entertaining! It feels like I'm playing an Initial D game or something, ahah! I'd really like to see more of this type of content in BeamNG, it's great! Also, how do you buy a new car? I remember in the delivery mission, the girl mechanic tells you to deliver the parts and then she will sell you a new car... Im looking on the map and I dont see any "garage" marker... do I just need to keep doing the missions for now?
The campaign is just an intro, you cannot buy a new car. It's just to show off how the game could evolve (I believe).
It could also be a feature they're working toward, and planning to use while fleshing out the existing story. I have noted in the past that Lua's read/write capabilities extend to BeamNG's scenario files. The only issue is that there's no way for the lua file to edit anything else, such as the .prefab file (to change the player's car or starting position, for instance), or the campaign or scenario JSON files (to change the order/presence of certain campaign chapters). I imagine that these are issues that the devs are working on, for this update, or the next. A Rocky Start does subtly hint at a diverging storyline, as the last race can be lost without needing to restart, and the end cinematic can reflect the failure.