No such thing as private plates in france, whenever you move house you have to re-register your car with the local authorities and they issue you a reg number that ties your car to that region - what a pain..
But CJ you are right about the foreigh cars here - and as I understand it if you own a place in france, you can register a car there, pay french tax/insurance (cheap) etc, but quite legally drive it over here.. as long as you reregister it there annually.. bit of a loophole! The reverse also applies, though you are 'supposed' to register a car there if it stays more than 6 months..
they have a nice loophole fro banned drivers too... the little 'Microcar' jobs, with their 500cc diesel lumps can be driven by anyone, with no licence required.. so a banned or unlicensed driver can still be quite mobile (albeit at a reduced speed!!!)
seem to have drifted off topic oops