Now this looks like old news but it doesnt seem to have been mentioned on here (feel free to have a go if it has). But in January 2012 France brought in a new law banning devices able to detect speed camera positions. Most sat navs these days are able to detect locations and as such are no longer sold in France with this feature.
After a bit of research all we need to do is disable the speed camera alerts on the satnav. Police are allowed to check the device and if found enabled then you can be hit with a fine of up to 1500 Euros!
So just a quick heads up to you all, be aware and either disable it before you go or sharpish if you get pulled over.
Heres some more info courtesy of Garmin:
http://www.garmin.com/uk/extras-camera-alerts/#france