The simple answer is that the French second-hand market is very different from the UK, and even from its neighbours who also drive on the right.
For example, in the UK it is much more common to have a company car. In France, these have been an exception rather than the rule and those who have one are heavily taxed, as are their employers.
Workers in cities instead get discounted public transport, such as the Navigo (formerly carte orange) which allows unlimited use of the metro, buses and RER network in Paris for around €1 a day.
In the UK, company cars are changed every few years and old ones feed into the used car network, lowering prices.
French garages face stricter regulations concerning used cars than in many other countries.
The garage is responsible for the car’s condition and has a legal obligation to explain this to the client, including, for example, if the vehicle is an ex-hire car, or if it has been involved in an accident.
This means that scandals such as having sawdust in gearboxes to mask odd noises happen less often in France.
When they do, the garage owner is likely to go to court.
In the UK, cases are handled by hard-pressed trading standards officers and only the most extreme cases end up before the magistrates.
Private buyers in France do not get the same protections as buying from a professional so fewer are prepared to do so.
Private sellers often price their vehicles according to guide prices found in L’Argus, based on analysis and predictions by the magazine staff, and are similar to blue book prices for professionals in the UK. Sellers, including private ones, must also supply a recent contrôle technique.
Another factor is that while the cost of labour charged by many French garages, especially in country areas, is lower than in the UK, the price of parts – until the new rules on second-hand parts having to be offered began – was often higher.
The government said in early March that it was working to change regulations limiting the supply of body-work parts to those provided by original manufacturers, but could face a long battle.
Previous governments said the same without managing it.
There are fewer scrap yards in France, with those that remain facing rules concerning the need for special tanks for oil, diesel and petrol, storage areas for batteries, and heavy environmental taxes.
Second-hand parts such as alternators are correspondingly more expensive.
Other government measures, such as the prime à la conversion to replace polluting cars, influence the market.
Traders said prices of cars aged between 11 and 15 years fell when it was introduced.
Meanwhile, prices of vehicles aged two to five years rose by a corresponding amount.
It means a lot of serviceable cars have gone for scrap, reducing the supply of second-hand cars. Prices are also affected by the cost of new vehicles.