Yes, the French do like their red tape... What started me thinking about registering the car in France was a recent change to the law in France on that subject. Since late last year, vehicles over 30 years old are eligible for 'Vehicule de Collection' status. This has a number of advantages, not least of which is cheap insurance (comparatively) and the requirement for a 'Controle Technique' test (French MoT) every five years instead of the usual two years. There are also far less stringent checks on Type Approval - basically as long as the headlights dip the right way, I think you're in the clear.
You do have to be able to prove residence status in France; i.e. utility bill, Tax bill etc, but anyone with a property in France will be able to do that. I've just done the first step, which is to go to the local 'Hotel des Impots' (Tax Office) with the necessary documentation and get a form which states that there is no VAT payable on the vehicle. Once that is done you have to download another form, fill it in and send it off with photos and further documents to a different department. Once they issue you with a further certificate, you're able to apply for the 'Carte Grise de Collection'. So it's a bit of a faff, but nothing that can't be overcome with a bit of tenacity.
There's a very good write up on a French site run by ex-pat Bikers (my first love is two wheels, I have to confess) which can be found here:
http://bikeclubfrance.com/forum/viewtopic.php?t=2013It refers to bikes, but the process is exactly the same for cars, as far as I can see.
Oh, and I'll post up a photo or two when I'm at my home computer...