Driftmoon doesn't have any vehicles yet, but there will be some later on. I don't think the vanilla Driftmoon will make use of them, but it's such a popular request for modders that I already have plans for implementation. Vehicles in Driftmoon might be a bit different, since we have physics - there could be several parts in a vehicle for example joined by joints. Remains to be seen.
Porting graphics should be a no-brainer. Driftmoon uses png and jpg images, and both games are top-down, so it will be a piece of cake. You're of course free to use any images from both Notrium and Driftmoon in your mod.
It might be a good idea to get started right away, I'm giving Driftmoon modders my full support, which means if something is not working, I'll fix it. And it's also fully forwards compatible, so if you start on your mod now, it should work with all future versions.