Adaptors readily available to borrow/buy at "proper" garages, most supermarkets/hypermarkets do NOT sell or hold them. I bought my own and it stays in the car.
Couple of points on using the adaptor .... do not overtighten .. just needs to be fingertight .. not even fist-tight .. that way it will not freeze on. When you insert the nozzle ensure the whole thing is vertical or the weight of the unit can slightly unscrew the adaptor leading to a cloud of gas and general panic from the locals.
Nozzels vary a lot more than the UK ones do ... release lever position can be a trigger on the side or a button on the top... sometimes worth a quick "play" before inserting into the adaptor, as if its in and you can't release it ..........

My records from the last trip (August) show the price varied from the equivalent of 81 p/litre on motorway services to the equivalent of 71 p/litre at a LeClerc Hypermarket. Prices do change MUCH faster in France .. the same outlet might have 3 prices in one day !!!
LPG is very readily available and if you use a satnav ...
http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=6055 (log in required)
or this site will give you local info on both petrol and GPL ( as LPG is called over there

)
http://www.prix-carburants.gouv.fr/index.phpIf you want to borrow my adapter you are welcome .. just have to work out how to get it to you .. but as you own an LPG car I'd advise getting your own .. TBH ..

HTH
