Zach missed a great one: plutonium.
Consider a cylindrical 250m x 20cm RTG (radioisotope thermoelectric generator) powered by several 2m x 1cm rods of vitrified plutonium, mounted axially in an electric car (the long-awaited Tesla Pu?) and wired to continuously charge the battery pack. It would be relatively straightforward to engineer a shielded casing that would prevent measurable exposure or release even in the most horrific accidents, yet would still be light enough to allow for excellent vehicle performance. Any possible RTG breach or attempt to circumvent safety protocols would be immediately reported via satellite radio to a national authority tasked with responding to such incidents.
- The vehicle is fueled once at the point of manufacture and never again.
- Charging would only be required when daily use exceeded the RTG output.
- RTGs retired from high-performance vehicles could be reinstalled in lower-performance vehicles.
- RTGs no longer suitable for vehicles could be daisy-chained to power homes or businesses.
- All Tesla Pu's would necessarily be fully autonomous and self-driving (see Cons).
- Adequate ventilation is required when the RTG is operating at full power, to prevent a "Chernobyl@Home" incident.
- Terrorist-spawning countries will need to be eliminated prior to starting full-scale vehicle production.
- Since all countries are capable of spawning terrorists, the human race will, sadly, be extinct before the first model hit the streets.