Hybrid cars today are all gas electric. The key is something called regenerative braking - where the energy used to stop the car is used to put a charge back in the batteries. It only gives about a 15% in MPG and is pretty expensive will all the Lithium batteries and heavy copper wound electric motor.

The energy from braking can also be captured using a flywheel, hydraulic fluid or compressing air. All have their advantages and disadvantages. A 4 hour stop for air every 125 miles in a tiny econobox is not going to sell in the US. It would be a nice commuter car if that's what you need.