If we're talking about the air car then lets be realistic. It's designed in France and will probably sell first in France. They produce 415 bkwh from nuclear (I believe this includes transmission losses, but I'm not sure), and export a significant portion of that (not sure how much exactly).
We know pressure=energy/volume, so the energy used to take the car ~150 miles is (350bars)*(400l)= (101325(350)N/M^2)*(.4)m^3= 14185500N*m or Joules. Now at 10% A/C efficiency, an aircar uses 141855000J per 150 miles. Assuming the average citizen of France drives 20 miles per day, they would use 6903610000J per year (150/20=7.5 days per fill, 365/7.5=48.7 fills per year, 48.7*141855000=6903610000J per year), or 1917kwh per year (6903610000/(60min*60s)=1917669w/hy=1917kw/hy). Assuming 25,000,000 air cars, this works out to an additional ~48 bkwh per year. Which could be covered by the construction of an additional 7 nuclear power plants. An A/C with 20% efficiency would cut this in half.
We are inefficient little bastards, and this kind of waste is rampant throughout our system (especially here in America). After a bit of pondering I think peak oil isn't as much about lack of energy as it is about those who have the most power (auto/oil industry), still having the most power after this transition.
A 2kw solar panel system will provide ~2700kwh per year and cost ~$20k. This leaves you with 800kwh per year extra. The cost of the car is ~10k...
So for 30k you could be able to drive almost 7500 miles per year, cut you electricity bill significantly for at least two decades. Fission is much cheaper than solar. As a matter of opinion, I'd say fission is so cheap that it scared the shit out of the oil/auto industry... enough to result in it's blacklisting until a time when it was needed.
Edit- For the sake of argument, in the U.S. (30 mile average per day, ~203 million cars) we'd need and additional 585bkwh per year. Which is somewhere in the neighborhood of 80 more reactors? This is why we're seeing this push towards clean coal. It's the only substance we have that could provide the increase in load needed while these fission plants are being contructed.
"Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost. "