A month after returning from an otherwise glorious trip to France I get a three-page letter saying that I was driving at 58km/h in a 50km/h zone. Then it says something about speed being 53km/h (la vitesse retenue est de: 53km/h).

Reading on, I think they are demanding a 90 Euro fine.

Has anyone encountered this? What is my recourse. What if I don't pay (I think I know the answer)?