Motoring: Fresh air in my hair, sun on my face: Given our climate, why do the British love open-tops so? John Simister has a theory

I HAVE just ground into central London through rain and stop-go traffic, on a journey typical of those undertaken by thousands of drivers daily. The last thing I wanted was contact with the outside air.

So why do British drivers demand sunroofs when our southerly Euro-cousins spurn them? And, stranger still, why do we hanker for yet more exposure - the topless car? If we worked out a ratio of open-top car designs produced over the years to sunny days in a typical summer, Britain would lead the world by a light-year.

The reason we love them is, in fact, quite simple. If sunny days are scarce, they should be enjoyed to the full. Britain also tends to have the right sort of sunny day, bright enough to give you a tan, not so fierce as to burn you or give you heatstroke. So a convertible car makes sense. Nor does the sun have to be shining. A crisp winter's morning, top down and heater on, is just the setting for an intimate encounter with the countryside. That might sound a hopelessly romantic notion, but cars are all about indulging fantasies.

Some sports cars only give real pleasure when the roof is open because they rattle, resonate and steam up when the cabin is closed in. Much of the pleasure of driving a TVR, say, comes from hearing the burble of its potent V8 engine. That's the sort of sound you do want to hear, and you will hear it the better when there is nothing in the way.

Driving in an open-top car, motorways suddenly become alien, dehumanising places and you search out the old routes that were the nation's arteries in gentler times. Combine this sense of discovery with the well-being that goes with fresh air and you cannot help but feel good.

But what if it rains? As long as you keep going, the air will flow over the car and you will stay dry. The trouble comes in a traffic jam, or during a hailstorm when the sharp ice chunks sting your eyes. Then it's time to admit defeat, and raise the roof.

This is easy in many modern convertibles, especially those whose hoods are raised by electrics or hydraulics, but try to erect the headgear of a Morgan or the 8.0-litre V10- engined Chrysler Viper, and you'll get so wet during the job that you might as well not have bothered. A wax jacket with hood, or a flying helmet, is essential wear in such a car.

If the fantasy is not to wear thin in the real world of traffic jams and rain, you need a convertible that can mimic a solid-roofed saloon or coupe when the roof is on. Volkswagen's open Golf does this particularly well, helped by a body that has lost little of its stiffness through losing its steel superstructure. This is not always true of open cars that started out closed, though purpose-built sports cars, such as a Mazda MX-5, are less prone to shake and shudder over bumps. Not that a little body flex is necessarily a bad thing; in the case of the Mini Convertible, it causes the legendary bouncing box to ride the bumps more smoothly than any Mini before it.

But the two-seater sports car is where the fondest friends are made. You don't see many Marinas and Cortinas left over from the Seventies, but MGs and Triumph Spitfires still provide pleasure for thousands. Fresh air in a fast car. In a world of increasing uniformity, it's one of life's great escapes.