LPG cars

I am looking for some information on LPG (Liquefied Petroleum Gas)?

Has anyone experience with changing a petrol car to LPG, and

is LPG 'autogas' in Switzerland?

All basic info welcome!

search for erdgas and you'll find a thread discussing this. In CH erdgas is CNG compressed natural gas, I don't think there us much or any LPG. As far as I know you can't convert an existing car to CNG but you might prove me wrong.

EDIT - found the thread