1200 miles and no speed cameras, you prob went too fast or your eyes are not looking for different shapes. Loads about. I did 2400 miles short time ago and every summer go to or thru France, cameras everywhere. This year a marked increase in mobile speed devices, I saw loads and only once pinched. I also found out from an ex-pat whose property we stayed at, that from July to August teams operate a 'run into the back of' that is they see foreign plate and you run into the back of them
Like most motorcyclists I am more alert towards speed cameras than when driving my car
and can honestly say I haven't seen any, I am not saying there aren't but I always looked upon France and other European countries as heaven compared to the UK.
As for the 'run into the back of' gangs, sounds a bit like the UK