Latest figures from Five Star - the AA's Continental breakdown service - show that nearly 20,000 claims were made last year.
Almost half of these were for emergency repairs, at an average of pounds 82.59 per job, while more than 3,600 claims were made to cover additional travel expenses, at an average of pounds 315.50 each. More than 2,000 cars had to be brought back to the UK - in some cases at a cost of pounds 2,000.
Tony Dunlop, managing director of Europ Assistance, points out that motorists who break down in France, for instance, are often unprepared for the costs involved.
'In the UK, 90 per cent of vehicle breakdowns are rectified on the roadside, allowing motorists to continue their journey. However, in France, most cars are taken to a garage for repair. This involves towing fees and usually an unscheduled overnight stop.'
Europ Assistance says that the average cost for roadside assistance in France is pounds 75, while up to pounds 100 is charged for towing fees. Hiring a car for two to three days costs between pounds 200 and pounds 300.
'In the worst case scenario, a motorist could face costs of well over pounds 1,000 for not having proper motoring breakdown insurance.'
The company's Family Continental Motoring Assistance scheme costs pounds 28 plus pounds 3.50 for every day of travel. Socover for a two-week holiday would be pounds 77.
This includes pre-departure protection of pounds 750 in case your car is stolen, involved in an accident or goes up in flames during the week before your holiday, as well as medical emergency cover and personal travel insurance for everyone travelling. The insured vehicle must be less than 16 years old.
The AA's Five Star Vehicle Cover costs pounds 41 for two weeks, or pounds 53 if you opt for Vehlcle Plus (only available for vehicles less than 10 years old). Personal insurance costs extra - pounds 15.45 per person for two weeks with children under four free, providing the rest of the party is covered.
The RAC Eurocover Insurance also distinguishes between Motoring Assistance and Personal Travel Insurance. Motoring Assistance costs pounds 49.95 for 10 to 16 days, with an additional premium of pounds 3 if you are not an RAC member, plus pounds 32.95 if your vehicle is more than 10 years old. Personal Travel Insurance costs pounds 18 per person for the same period, with children under four free.
Mondial Assistance's Traveller Abroad policies cost pounds 44 for 11 to 17 days, or pounds 66 if the car is between 11 and 15 years old. Medical and personal cover costs an additional pounds 17 per adult and pounds 13.50 for children aged four to 15.
All of the policies will cover the cost of finding and delivering any spare parts you might need, or the cost of repatriating your car if it cannot be repaired. Beyond that, there are differences: the AA, for instance, will pay pounds 50 compensation if someone breaks into your car - Europ Assistance offers up to pounds 175 following a break-in to make your vehicle secure.
Of course, if you take your car abroad more than once or twice a year, there are other policies that might be more suitable. AA members can pay an extra pounds 49.50 a year for AA Europe, which provides the same benefits as Five Star Vehicle Plus. For non-nembers, the Frequent Traveller policy costs pounds 125 a year.
Membership of the RAC Reflex Europe starts at pounds 155 a year. This provides cover in both the UK and Europe. Mondial's Traveller Abroad is available as an annual policy for pounds 90 a year, while its Roadservice Gold is another option at pounds 99 a year.
Jane Meckiffe who lives near Liphook, in Hampshire, paid pounds 131.50 for an annual policy with Europ Assistance - and is very glad she did. She drives back and forth with friends to Lugano, Switzerland, five or six times a year. On a trip last March, she stopped as usual for an overnight stay at a hotel in Alsace-Lorraine.
That evening, because the car (an automatic Honda Concerto) contained all the luggage, she decided it would be advisable to move it into a better-lit spot. However, it had been parked by one of her friends and the seat had been pulled forward.
'Stupidly I didn't bother to adjust the seat,' she says. 'So when I switched on and put the car into gear I found my foot was wedged under the wheel and on the accelerator. I went off like a rocket. I managed to swerve to avoid other parked cars, went up on the grass and hit a tree. I was lucky not to be hurt, but the car sustained considerable damage.'
Once she had calmed down, Ms Meckiffe rang Europ Assistance. The company arranged for a garage to remove the car and later brought it back to England for repair. It also arranged a hire car so she could continue her holiday. 'They couldn't have been nicer or more efficient,' she says. 'My insurance company dealt with the repairs here, but Europ Assistance footed the bill for everything else.'
AA Five Star 0800-800555, Europ Assistance 0444-442211, RAC 0800-550055, Mondial Assistance 081-681 2525