If you're a passenger, how would you tell the human driver that there's an open parking spot 4 rows over, 3 spots in? I imagine you'd be able to tell an automated car the same way.
The passenger is a human who can understand language at a human level and even then we get it wrong a lot. We currently have no computers capable of even close to that sort of level of capability and are in no danger of getting it soon.
It's probably even easier, as the automated car will likely have something like a touch screen for input, which can show you on a map and/or on a camera view exactly which spot it's taking you to. If it's the wrong one, you can correct the car verbally, or even just tap on the correct space on the touch screen.
If you are bothering to use a touch screen then you are controlling the vehicle and you may as well just grab the wheel yourself. The car can override you if you look like you will his something. Seriously, do you REALLY want to navigate a car via iPad? "Computer... wait you passed the spot. No I didn't mean that one I meant the one over there. Tap, tap, tap.... Stupid computer..." Seriously, I think you really haven't thought this through at all. You're thinking it'll be some Jetson's technology that will magically infer your intentions in fine grained detail and I think you have no idea how difficult that human interface problem really is.
Ah, I think the problem is that you're thinking of automated cars like airline flights, where you buy a ticket to a destination before you head out, and once you board you can't change anything.
Not at all. I'm pointing out that communicating anything much more complicated than an address or an intersection is going to be a REALLY hard problem to solve. I'm not saying it's impossible but it is going to be super hard to do well. Basically I don't think we are going to be able to strip out driving controls from most vehicles for a very long time.