Off to the Revolution by a 2CV (2001)

As April 25, 1974 dawns, 25-year-old Marco, an Italian, and his Portuguese friend Victor leave Paris on a yellow Citroen 2CV. They are bound for Lisbon, which on that night was freed from Europe's longest dictatorship. The two are joined by Claire, Victor's former girlfriend and University classmate, who wants to take a break from everyday life (including her husband and baby son) to form again, even for a few days, a traveling trio with her friends.