Has been done (1992 apparently):-
The Saab 9000 drive-by-wire ‘Joystick’ project
Google for [saab joystick steering] turns up quite a few hits.
I did once see a Mini parked on the road that was apparently steered by a tiny (RC model sized) joystick on the floor. I assumed it was for the use of someone with no or non-functional arms. It must have cost a *fortune* at the time. I think I saw the car in the 1970s and it was a 1960s mini in utterly pristine condition.