All has been said really - do as the local camping caristes do. But, be prepared for them to want to park close to you if the aire is busy. This can be a bit disconcerting at first, because if there's room, they'll park - no 6 metre rule on aires!
My idea of hell lol.......if there's another van within 500 feet of mine im in the wrong placeWe have been on aires galore. Do as the others do, probably not a good idea to light up a charcoal barbie, but a gas cadac in the right place has always worked for us.
Have been on aires during bank hols where you almost have to go through other vans to get to your own. Sometimes they are empty, so use your loaf.
Here's what we found at the entrance to the large forested Biscarrosse-Plage aire the last time we visited:
Basically aimed at the annual New Age Traveller colony that occupies one corner of the aire all summer, and roundly ignored by all, especially by the New Age Traveller colony. The bloke who made a rather half-hearted attempt to collect the fees looked totally overwhelmed.
Nice spot, if you don't end up among the New Age etc...