bluskis,
Sounds as if you may have had some interesting experiences in France - could you elaborate on what sort of formalities you have run up against?
I clear customs at the northern airfields and then continue on free from further bureaucratic constraints. I've never had any interest from officials further south either, though most of the places I've been are small fields like La Baule, Habsheim etc. La Rochelle is the only one of any size, but that too seemed very laid back.