Looking at this years tarrif brochure, it says:
NEW: A special area will be reserved for motorhomes in Parc Bleu, Rouge and Antares. Parking forbidden in the others.
This note is under the heading for 'Car Parks'. It does not mention any restriction under the 'Aires D'accueil' heading, but buses are interdit. It does, however, say that the pitches should be 7m x 5m.
DB