Pretty cool set-up!

There's a company in India that makes a small lightweight air-powered car.  It has two super-high pressure carbon fiber air tanks under the floor and is driven by an air motor.  You can recharge the tanks overnight with a special compressor, or exchange the tanks at a "gas station."  The speed, range and performance are pretty good for getting around town.

I've often thought that it would be a cool project to make a hybrid using a Volks Compressor (a 1600 air-cooled type 1 engine converted to run the engine on 2 cylinders and pump air with the other two).  Store up compressed air and use it for acceleration, then cruise on two cylinders.