I''m just an artist, not an engineer, so this is just me speaking off the cuff. I'd say it might be done with magnetic fields, but think of the ripples of change that would have to come about to make it work. Computer and electronic architecture would have to change to protect memory from the fields being generated by the vehicle or roadbed, or both. The ripples would extend to the technology used in credit cards and id/keytag cards. Old style mechanical watches might have to become a thing of the past.
I know some would point to maglev trains to question the changes I see, but the maglev trains that I know of have limited or restricted access to the areas of the magnetic fields. Mead's artwork shows people interacting with their cars the way it happens with current car technology. I did work in the cable TV industry for many years so I know of at least one person who had to get his bank and credit cards replaced after he didn't think about how he was carrying a failed klystron amplifier assembly he had just removed from the overall unit. If Mead's cars are floating on magnetic fields, which would have to be stronger, just standing near the car could wipe your cards. Again. This is off the cuff, so feel free to shoot me down.
Edit added later.
Oh. Something else I should point out. If those cars did run on magnetic fields, I likely could not operate one or be around them - for the same reason I can no longer have MRIs. I have metal in my back from major back surgery.
