On a visit to Brisbane I had a test drive of Shaun Williams' battery powered Electric-Echo car. Shawn commented that the Mercedes Benz A Class car I arrived in would be a good choice for similar conversion to an electric car.
The A Class has a sandwich floor, with an empty space under the passenger cabin. According to BCC and Times car reviewer, Jeremy Clarkson, "... the A-class had been originally conceived as an electric car and the cavity had been created as somewhere to store the batteries".
There was a prototype electric a-class but using the advanced ZEBRA sodium/nickel chloride battery technology and Mercedes are now trying the same technology in the smaller Smart car and it is also used in the Indian Reva NXG Electric Car.
The A class also makes efficient use of space. The result is a small car with a large load. This is especially important for energy efficient cars. The space in the A class is shown by these two photos, the first shows a skeptical office supplies employee wondering how a four drawer filing cabinet will fit in such a small car (the counter staff had asked if the vehicles was a four wheel drive, assuming that one was needed). The second photo shows the cabinet in the car, with room left for three people.
Mercedes-Benz have produced a S-Class Hybrid prototype. Perhaps some of the technology will trickle down to the A-Class.