After so many experts have warned us that the cost of car insurance is on the rise, what's happened? It's fallen! It's mostly down to the growing impact of shopping online.

In the second half of 2005 the average car insurance premium fell from 470.17 to 462.15. But it's the silver surfers who've benefited most. During the last six months of last year, drivers over the age of 65 have seen their average premium fall by 4.5% from 342 to 347. What is most surprising are the huge differences in premiums between providers. Differences of 40% between the most expensive and the cheapest are common.

It seems that most motorists are not aware of this as every year, half of them automatically renew their insurance with their existing insurer. A further 19% only bother to get one competitive quotation.

And readers will be surprised who sells the expensive policies. A recent survey in Which, the consumer magazine, shows that Norwich Union - the UK's biggest insurer - failed to come top in any of the 36 driver categories surveyed. Direct Line, another well-known name, only managed one top spot.

This is down to the marketing strategies of the big brand names. They have been building up their client base with low prices and heavy advertising and then gradually increase prices. They are clearly relying on apathy and brand loyalty to keep their clients. And with 50% automatically renewing, it works!

But if you decide to shop around, be careful. A low price isn't everything. Some policies have mouth-wateringly low prices but skimp elsewhere.

For example, when your car is being repaired, do you want a courtesy car? Some policies only pay 100 or so for stolen audio equipment. Is that enough? Do you want to insure your personal belongings whilst they're in your car? And crucially, some comprehensive policies won't provide third party cover if you to drive another person's car - even with their permission!

Before you decide, it's wise to consider all these aspects.

But going back to price, if you think prices are cheapest on the Internet, you're right! Internet quotations are normally 5% - 10% cheaper than telephone quotes.

When Internet shopping, most people look for the cheapest quote and then read the details about the cheapest policy to check out that they provide the cover that's needed. You can hunt for the best deals by searching under car insurance but some of the discount insurance sites are more easily found if you type in discount car insurance or cheap car insurance.

But please remember, when renewal time comes around go shopping again. Don't automatically renew! It's so easy on the Internet as I found this year. My previous insurer quoted me 945 and I eventually bought it for 702. A saving of 243 for 30 minutes work.