Hiring a car is likely to prove extremely difficult, if not impossible. As it's usually cheaper to make the hire arrangements in this country, rather than on arrival, I suggest phoning round Hertz, Budget, etc to see what they say.
The French Tourist Office, in London, might be able to tell you whether it would be possible to hire a car in France. You can e-mail them, here:
[email protected]
Alternatively, for a faster response, phone on 09068 244 123 (You should be aware that this is a premium rate number, charged at 60p/minute).
If you do manage to hire a car, remember that, because you've held a full licence for less than 2 years, you'll have to drive within the 'wet weather' speed limits even when it's not raining:
http://www.drivingabroad.co.uk/content.aspx?page=driving -in-france&navid=13
Chris