In reply to steve taylor:
LHD cars in the UK are more expensive than RHD, so by the time you've done everything to import it to France, you might just as well have purchased a car in France.
I've imported 2 UK cars into France (both RHD) and it's fairly hassle free to be honest and I don't really find it to be a problem not having LHD.
To import a car, you need to get the European certificate of conformity from the manufacturer. You can do this yourself or use a site like EuroCOC. This can cost anywhere between £75-200 depending on manufacturer. You need to go to the local tax office and declare that you're importing the vehicle. I thinks it's tax free if the car is over a certain age or done more than a certain amount of miles. I never had to pay import duty on my 2. You need to change your headlights to European ones because you can't get through a french controle technique (MOT) with just the stickers on the lights. Some makes of car allow you to do this without changing the whole lamp assembly, others like mine need the lamp assembly changed. For my RAV 4, buying the lights and getting a garage to change them cost about €400 in total.
When the car has passed the CT, you then take the CT certificate, Certificate of Conformity and import document to the prefecture who will issue the carte grise. Again, depending on make, model and age of the car the fee for this varies. They have something which translates as fiscal horsepower which they use to calculate this. Each car has a fiscal horsepower which is a calculated by some crazy formula and then they multiply this number by a fixed amount depending on what department you're in. For an average car, this is usually about €250-400.
Once you have your carte grise, you can then get some French number plates and French insurance wnd then send the your V5 back to the DVLA to let them know that you have exported the vehicle.
Simples.