Can I use the French aires to camp overnight? I have a VW Transporter van with a bed, 2 dogs, a camping stove and bottled water and loo bottle. I want to be safe but I don't need the constraints of a true camper van.
The link provided in the comment is a good one.
In France you are allowed to do "free" camping, provided that you respect a few things:
You can't do free camping in regional or national parks (as stated in the comment from Nate Eldredge)
You have to take any rubbish with you and dispose of them in appropriate places
DO NOT stay the night in highway stops! It is forbidden, but much more important, it is dangerous to do so. You are at a clear risk of being stolen / mugged. It does not happen often because people almost never do it (sleeping there). If you want to make a stop during a longer trip, quit the highway and find a spot in the countryside, near a small village.
In some places (towns/villages), it is required to go to a specific area for camper vans (should be easy to see this at the information office of the said town). At no charge. But honestly you can probably 99% of the time find a quiet place somewhere where you will be able to spend the night, and where you will not be disturbed. You can ask the local people for advice. Despite being French, they might be of help ;-)
It is very common to find old combis VW on car parks near beaches. in the north of France (north from Bordeaux), it is most of the time very well accepted and safe. South of it, I don't know.
You need to take car of your dogs' poo... in urban areas. In the woods, no need :-) !
It is better to be safe than sorry when it comes to using the Aire de Service sites. There have been a variety of stories in the press in recent times where people have had some form of gas used in the air vents of motorhomes so that thieves can gain access and steal items from them. Please take care not to use the motorway stations overnight and use either a non motorway Aire de Service or to use a proper campsite. There is a book available from places such as amazon for the Aire de Service or look at the local tourist information website. Failing that for proper campsites take a look at Go Camp France