As I understand things, from previous threads, there are no problems with using satnavs in France. The confiscation bit applies to speed camera detectors. If you have one in your possession and get stopped by the Gendarmerie, you will be fined a lot and the gadget confiscated whether it is switched on or not. There is no problem with satnavs which have the positions of fixed speed cameras in their database, but to be on the safe side, I always switch the camera data electrickery off. You can never be sure with the Gendarmerie. They are a law unto themselves, especially the Gendarmerie Nationale.
Hi skiptonmel I have got a garmin nuvi 250w. I used it in France last year with no problems at all. As Dickers and Trooper said it is the speed camera detectors which they don't like. Saying that I think you have more chance of getting stopped just because you have a british number plate. I have been going to France for the last 8 years and have never had a problem with the police. The only time they spoke to us was to warn us not to stop overnight on that particular aire.