Boy this is an amazing project. I wanna put a Chucky doll on it and creep out my neighbors!
How am I only seeing this NOW!?!?
What motor are you using for the steering?
There isn't any proportional feedback I didn't really had access (or money) to a lot of different actuators, so I pretty much had to use what I could find. It has end-off-switches, but its travel is about 1cm too long for the steering - so I had to make a switch to turn it off (when it doesn’t work the actuator is so strong it bends the metal-plate supporting it, which sadly has happened a couple of times). Other directions than left/right is time-based.
Perhaps you can fit a pot where the front wheels pivot or somewhere nearby with a linkage. Then you could use an analog input to monitor the position and prevent the actuator from exceeding its limits as well as giving precise control over steering. Looking at the steering video I'd probably mount it underneath with a linkage to where the original steering wheel connected. You might even get a 75mm slide pot in there as travel seems limited.