I saw a twitter post that makes me think that if you have driven to the resort that you are supposed to go to the front desk and tell them you have a car. Now if this is true, how many of us would really do this???? Without changing the process for entering/existing a resort, enforcing seems to be extremely challenging.
The Dolphin and Swan are able to enforce this fairly easily. When you go to park your car, you get a ticket at the gate entrance. You present the ticket when you exit. Also, upon check-in, if I recall when I stayed there, they asked if you had a car. So this would allow me in/out privileges. Otherwise I would have to pay every time I left the parking lot.
I do not believe that Disney is going to invest in the infrastructure to correctly monitor this and enforce this. If they did, then that would eat into the profits that they are probably trying to get from this entire situation. So I guess we will all have to wait and see what happens.