I have bought cars in France for a number of years, very rarely selling them, however, as I usually wear them into the breakers. I must have sold just one, my dear little red Corsa which was bought to replace a decrepit old Renault 5.
The brave little Renault had done stirling service being taken, overloaded to university in Bristol for a year, suffering Bristol rain, and very little usage during that time. Bristol is a car-unfriendly city, or rather, a public-transport-friendly city so basically you have to take the bus into the centre or take out a second mortgage to pay the parking.
However, at the end of its days it was leaking, had no heating and the engine kept overheating. I was pregnant with my eldest and so it had to go. I chose the car, the colour and the number of doors. I had to fight to have 5 doors as my ex thought it looked better with three. I insisted that 5 were better for transporting a baby about and, as he would not be doing any transporting of babies, he came round to agreeing. The car was sold when we went to the US, for the Argus price.
Argus is the nationally-recognised table of car values so if you see a car on sale for the 'prix Argus' you know they are referring to that table. You can look it up on the internet, natch, but not on the Argus website as you have to pay for their estimations. Instead, go to La Centrale where it's all free. You can even personalise your quote putting in the number of previous owners and kilometrage. Handy stuff.
I've been using it a lot to suss out Peugeot 406 break prices. For some obscure reason, most of them seem to be for sale up north. Most inconvenient.
Anyway, once you have found a car, you have to make sure it has a valid 'controle technique', less than 4 months old. It seems that some people don't know that it is up to the seller to get this, and try to palm the obligation off onto the unsuspecting buyer. This is illegal and results in an annulation of the sale, with all costs paid by the seller. You have to know whether the car you are buying is in a legal state of working order. Normal really. Legal obligations can be sensible when they put their minds to it!
The seller also needs to give you a 'certificat de non-gage'. This is a handy piece of paper which tells you that the car does not really belong to a credit company, or have hundreds of euros worth of parking tickets outstanding. You can obtain this now on the internet instead of traipsing along to the Prefecture. When I say 'need' of course, I mean he has to give it to you. Along with the form 'Certificat de Cession' which has to be filled in in triplicate (or photocopied??). Just for the fun, you also have to fill in the 'Declaration d'achat d'un vehicule d'occasion' because I'm sure you thought you were getting off lightly with all this form-filling business. Don't forget, this is France. Forms are an essential part of their cultural identity...
Get along to the Prefecture with all your bits of paper, including the old carte grise, barred and signed 'vendu le' with date and hour, and signed by everyone and his granny. I think you have max of a month to do that, or you're in BIG trouble.
I have all this to look forward to when I finally find the little 406 of my dreams. Hopefully locally!