The wind in your hair and an icy blast from insurers

Britons won't be parted from their convertibles, despite the high cost of premiums and the risk of theft. Melanie Bien reports

If BMW's new Z4 convertible is top of your summer shopping list, you are likely to be in good company. Despite the notoriously unpredictable British weather, motorists in this country are the biggest buyers of convertible cars in Europe, after the Germans. Even though we don't enjoy a sunny Mediterranean climate, we buy around 60,000 convertibles a year - twice as many as the Italians and 10 times as many as the Spanish.

But if you are new to topless driving and are switching from a saloon for the first time, you are likely to be shocked by the cost of insurance. Insurers see soft-tops as a much greater risk, and charge hundreds of pounds more in premiums accordingly.

"Convertibles tend to be in a higher insurance group than similar cars with hard tops, reflecting higher repair costs and security," says Mike Pickard, head of underwriting at insurer esure.

Churchill Insurance classifies a convertible as one insurance group higher than an equivalent car with a hard top. But classifications vary not only between insurers but also from car to car; two or three times higher is not unheard of, according to esure.

For example, a 35-year-old female accountant living in Wimbledon and keeping her BMW 330Ci Club Sport Coupe in a garage at night would pay £853.65 a year for cover from Churchill. But if she treated herself to the convertible instead, her premiums would soar to £969.15 a year.

The main problem is that while drivers love open-top motoring, so do thieves.

"Soft-tops attract the highest premiums because they pose a higher security risk," says Simon Ziviani at Privilege Insurance, a sister company of Direct Line. "This is exaggerated by the fact that many convertibles are at the top end of the range for performance, so premiums do tend to be higher anyway."

Privilege specialises in covering higher-premium vehicles, and about 15 per cent of its book this year is made up of convertibles. Most claims involve theft or damage caused while thieves try to break into the car, so the insurer insists on a tracking system or an immobiliser before it will cover higher-performance convertibles. It also recommends that all owners of convertibles put them in a garage at night. However, such precautions won't even earn you a discount.

Not only are convertibles easier to break into than hard-tops, they cost more to buy in the first place and are not as safe as saloons when involved in accidents. But if you still want one, shop around for the insurance as much as you would for the car itself.

If you opt for one of this summer's budget convertibles, for example the Ford Streetka or the Citroën C3 Pluriel, your premiums won't be as prohibitive as if you had purchased a top-of-the-range cabriolet. They will be higher than if you had bought a hard-top Ka or C3, but still cheaper than for, say, an Audi A4 Cabriolet.

Alternatively, you might want to go for one of the convertibles with a metal roof - such as that found on the Peugeot 206 coupe cabriolet - rather than a fabric one. But you shouldn't assume that premiums will be lower as a result.

"There is still the risk that you will leave the roof open and the car un-attended," says Mr Pickard at esure. "In terms of insurance, we are talking about the same sort of price."

Mr Pickard also recommends that convertible drivers take measures to minimise the risks. "Never leave anything in a soft-top car, as all a thief needs is a knife and he is in," he warns.

"Drivers should always raise and secure the roof if they are leaving their car, even if it is only for a short while," adds Mr Pickard. "Parking spaces should always be chosen carefully as well - in a busy street, in well-used car parks or near CCTV. And overnight you should use a garage."

And be prepared to pay a higher excess for theft from a convertible. While most insurers have a £100 excess for a hard-top, many will insist on £150 or even £200 for a convertible.

It is also worth avoiding a soft-top if you are relatively young. Older drivers will get lower premiums anyway than teenagers who have just passed their tests, and owning a convertible will stretch that gap still further. So if you are a fresh-faced 18-year-old with designs on a Beetle Cabriolet, it might be worth waiting until you are a few years older.