Vamos 3 is the Dune du Pyla near Arcachon in south-west France, the highest sand dune in Europe.
Factory 2 is the Panhard works in Avenue d'Ivry, Paris.
The car that links them is the Citroën 2CV Sahara - that's the 4x4 model with two engines, one in the front and one in the rear. These were built in the Panhard factory in Paris (Citroën had a financial interest in Panhard from the mid 1950s onwards), and in a publicity stunt in 1961, a 2CV Sahara became the first car to be driven to the top of the Dune du Pyla under its own power.