Unfortunately that won't work because I'm on the other side of the world. It won't even work on Skype because the internet here is heavily under-invested and very slow. But the story is pretty simple.

The money in car rental is made on the insurance. Don't take out the maximum insurance and the rental company might well find damage on the car after its return that it then bills to your credit card. Outfits like www.insurance4carhire.co.uk offer much cheaper annual cover. But if you have this rather than the rental company's insurance then the rental company is more likely to find damage. The golden rule on returning a car is to arrive at least four hours before your flight. Then you have time to make absolutely sure you go over the car with the rental rep and the damage sheet and take at least 40 photos of the car: wheel rims, bumpers, everything, so they can't bill you for damage you did not do. Get back to the airport with only minutes to spare and you are asking to be ripped off.

Two other rip-offs include excess charges for Portuguese tolls. There are no tollbooths on a main stretch of motorway so you have to buy tickets from shops, and many hirers are not told about this. Also paying for a full tank of petrol whether you use it or not, and whether you fill the tank before returning the car or not.

Update: Watchdog Daily covered Private Parking Charges brilliantly in November. It’s a very solid programme.