Most Britons driving abroad risk fines, penalties and accidents because they are unaware of motoring regulations, a survey by RAC Legal Services has found.
It is illegal to make rude gestures at other motorists in Germany
Just 18% of 2,500 motorists polled claimed any understanding of France's laws, while it was 10% for Spain, and 7% for the Irish Republic and Germany.
None knew about laws in new EU states such as Slovakia, Latvia or Lithuania.
The RAC said "simple preparation" could help people avoid fines or accidents - "all of which can ruin your holiday".
RAC Legal Services spokesman Philip Hale said: "Millions of us travel in Europe by car each year, but it seems few understand even the basic traffic laws.
"Exceed the speed limit, park on the wrong side of the street or drive without headlights and you could end up in trouble, depending on the country you're visiting."
The report highlighted unusual European motoring regulations including:
- In some towns in France and Spain, parking is allowed on one side of the street in the first half of the month, then switches to the opposite side.
- On motorways in Italy, it is illegal for a motorist to leave their vehicle without wearing a reflective jacket.
- Using a hand-held mobile phone while driving in the Netherlands earns a 136 euro on-the-spot fine (about £92) - the highest in the EU.
- Drivers can be fined for running out of petrol on motorways in Germany.
- Rude gestures or swearing at other motorists is illegal in Germany and can lead to on-the-spot fines.