The Tesla EV Roadster is a fine looking and well powered vehicle. I promote any vehicle that does not run on gasoline, even if it does not split water.
0-60 in 4 seconds, runs on ~6800 lithium ion laptop batteries. Impressive. It must have a few hundred good horses in there, electric. This is the electric car that will beat the bag out of gas cars.
A few weeks ago I designed the 2008 Grand Marquis to use certain power sources, either battery/air, biodiesel, or fuel cell. I would like to add to that and replace the power source with a water splitter. A 1994 Ford Escort can do it, so can a largecar. I estimate that this will reduce engine weight by perhaps 200-300 pounds, considering loss of catalytic converters and mufflering and consolidated air intake and radiation systems.
I would replace the transmission with a multitronic transmission, sparing time getting high and increasing efficiency and available torque. This too will reduce moving parts and weight of the vehicle by perhaps 100 pounds.
And, if we can create hydrogen heat hotter than the surface of the sun with the H20-HHO-2H2O2 method for *free*, we can afford to extrude carbon fiber without the cost of heating it. This will reduce the cost of carbon fiber to perhaps 1/5 of its current cost, $15/pound, even without new refining strategies. This will make carbon fiber within price range for the vehicle, and allow the 800 pound carbon fiber frame even on this monster. We could afford to reinforce it with carbon threaded nanotubules if necessary to give it the highest tensile strength of any known fiber. Excellent.
This will bring the car down to the $15000 price range or lower considering the costs of operation, and allow it to achieve unreasonable acceleration, pointless efficiency, and 5*+ safety rating. Let the games begin.