The thing why this was only a research project and never came into mass production was regulatory stuff, IIRC?
(most EU countries require, still until today, a "physical connection between steering wheel and wheels" in their trafic regulation)
From what I've read the test drivers also thought the car was too difficult to drive, with the joystick being too reactive. I wonder how much of that could be solved today with modern software and stability control tech.
I can't find it now, but I do remember a similar prototype with mechanical wires (not electrical) that was supposed to solve the regulatory requirements. That joystick looked more like a cyclic control from a helicopter.
Also funny that they had the ability to swap to the passenger to drive it. So acceleration/break for one person, steering for another? Really not a good idea.