Thanks for that, Nicolas. As ever, you are a mine of invaluable information!
I made the assumption that simply having the .LNG files for the absent languages somewhere on the laptop would be enough. I have those on the V32 update disc, for example. I would like to get the NavCoder working and have ordered a Resler cable to give it a try.
It would appear that Yves' problem could best be solved by swapping out his existing satnav for one with French already an option in the firmware. As I said, I have an Italian/French/German unit available, but that is a late 2005 Mk4, and I don't know if it would be a straight swap for him, depending what he has already installed in the car. If it is, then that would probably be the cheapest solution, if not even the ONLY solution. Certainly easier than trying to re-code the existing unit. Maybe you could ask if you speak/mail with him? If it were a retro-fitted Mk4 he has in the car, I would just swap with him, but I assume it will be an MGR Mk3. I asked him if it had "DVD" emblazoned on the front of the unit, but got no response