A robot is nothing without wheels. That's why I have started experimenting with them already:
This test vehicle already drives over the edge very dramatically.
How it currently works, the technical side: The round rolling, actual wheel parts are separate Unity Rigidbodies, with Hinge Joint components making them act like the were attached to an actual axis. All those Hinge Joints connect to the Rigidbody of the main vehicle.
There currently is still some hassle with getting the wheels to the right position when loading them from file, mainly because they don't yet find the main vehicle Rigidbody, which has also just been loaded from file. Thus, in the actual editor, they currently still act like having a seizure. But at least this test vehicle works fine.