Learned recently that it will become compulsory from April 2012 to carry a breathalyser test kit in your car whilst in France. Failure to do so will result in a fine so this is now something else you need to carry besides your warning triangle, spare bulb kit etc.
There is a feeling about that as spring approaches and knowledge of this requirement becomes more widespread the price of these kits will increase dramatically. I was made aware of this through another motoring forum. Anyway, now is the time to go shopping for a kit if you think you might take your MX5 to France this year.
You can buy a kit of 3 "sticks" for about £5 plus postage on various websites and need to purchase the kit that measures a breath alcohol content (BAC) of 0.05.
........and if you think I am taking the p***, sorry just couldn't resist the pun, then google France and Breathalyser 
As an aside it will also become illegal to use any kind of speed camera warning device in your car including satnavs that contain a database of camera locations. The fines for that will be horrendous and even TomTom are now erasing the French data from all their updates.
Happy days!