Ok, so how about if you can drag a representation of the car to the place on the map where you want it to go? This doesn't seem like a very difficult UI issue to me.

That depends entirely on the quality of the touch screen interface. Most GPS navigators are just terrible. The precision you get with a normal tablet or smartphone is just astonishing in comparison. Sometimes I'm pissed because I have troubles aiming a link which is 1/10 the size of my finger (a desktop site rendered on my phone) ...

Ever used the equivalent system built into a 2019 model car where the absence of a steering wheel and other driving instruments mean that the interface could be two feet wide and easily zoomed for precise navigation?

Current GPS devices are built to be cheap, compact and work with limited connectivity. I think we'll see amazing things in 5-10 years.