An even greater problem for Aptera, and for that matter any other competitor in the FE race is what do you register it as. If it's a car then they have to deal with all those pesky government regulations such as crash standards, etc. I know of one person in the Seattle area creating an all electric kit car that will be registered as a motorcycle (1200# empty) to avoid regulation. You notice Aptera calls it a vehicle and not a car.
Back to the question, gasoline would be about the easiest conversion to make. I hope I'm wrong, but I fear "unusual" designs like the Aptera will suffer a similar fate as the Segway. People as a whole are mostly conservative when it comes to parting with large sums of money.
The practical side to FE is that with the growing standard of living globally and the increase in automobiles, there is just not going to be enough oil to power them all. It doesn't take a genius to know that with future fossil fuels being in short supply electricity is the only real solution. Which by the way is right where Aptera is situated.
