No, this isn't a French film. It's a 2 part TV miniseries starring Ben Miles, Fay Ripley, Daniel Ryan, and Rachael Blake. The perfect summer film to watch, and even though how they end up in these predicaments is a little far fetched (anyone who would take such an old car to travel through Europe is just asking for trouble), I think it ends up being a superior suspense/horror film. Much better than most of the big screen scare films released these days.
The plot is a couple (Miles and Blake) and their two kids take dad's old Merc and go on summer holiday, camping through France. They are quickly befriended by a strange couple (Ripley and Ryan), who seem to keep stalking them in a big camper. The action and suspense really picks up halfway through episode 1, and remains steady through the end of the 2nd part. If you haven't seen it, it's well worth a watch. Emily Beecham gives a good performance as the daughter who defies dad, and wants to hang out with a partying French guy she just met at camp. It's listed on IMDB as her first film.
I thought it kept a good pace throughout. In fact, I saw there were 3 minutes remaining on the DVD and couldn't figure out how everything was going to finish up in such little time. The tension literally went right through to the final seconds.