Compressing air is very inefficient. The kitty-car sounds like an early April Fool's joke.
Here is a paste from the article:
"Its steering wheel is equipped with a 5kW electric moto-alternator. This motor acts as the:
* Motor to compress air
* Starting motor
* Alternator for recharging the battery
* Electric moderator/brake
* Temporary power supply (e.g. for parking)"
Dang, I don't think I could produce 5kw by spinning a steering wheel. This vehicle is for the serious bodybuilder only.