In the old days, you bought an estate car for a simple reason: you needed more boot space than a saloon. It was a utilitarian vehicle, as all good cars should be.

Sure, there was a tiny bit of pretension - after all, the very term "estate" conjured up images of the idyllic rustic lifestyle so adored by the English. Old-fashioned estates were sometimes known as "shooting brakes" to suggest scenes of Edwardian shooting parties, with a James Mason-like character as your titled host. None the less, estate cars were born to lug loads which saloons simply could not accommodate.

How different things are now. Pop into your local dealer and you'll be shown small estates, sports estates, luxury estates, lifestyle estates and - the newest fad - off-roading estates. Even the police choose estate cars as chase cars nowadays and, a few years back, Volvo used one of its estate models to compete in the British Touring Car Championship.

Four very different estates have passed through my hands recently. First up was one of the recently revised Mercedes C class. This is known, in motor industry-speak, as a lifestyle estate. It's more of a giant hatchback than a true estate, and it's aimed at people with busy, sporty lifestyles who need space for skis and tennis rackets but don't spend much time at B&Q or in antique shops. Other lifestyle estates include the BMW 3-series touring, the Volvo V40 and the Audi A4 Avant. None has a big carrying area, which is a polite way of saying that, although they may be good big hatchbacks, they are not good estates.

Next up was the Volkswagen Passat Syncro V6 estate, the top model in the new Passat estate range. Although not as roomy as an old-style Volvo estate, it has a much better standard of finish, and drives much better. If I wanted a new estate I'd buy a Passat, but not the Syncro V6 model, which at pounds 25,000 is rather pricey.

Stick with one of the turbodiesel or petrol front-drive models, and feel smug every time you see a far pricier, but no better, Mercedes or Volvo pass by.

A Volvo V70R AWD came next. This is a Volvo estate unlike any other Volvo estate, more motorway racer than protective shell for motorists of a nervous disposition. The standard V70 is Britain's best-seller, the stylish heir to the old green wellie, labrador and luvvy type of Volvo.

But in V70R AWD (for All Wheel Drive) mode it epitomises New Volvo, a firm fast breaking away from its "sensible shoes" image and eager to make the motoring equivalent of multi-coloured air-cushioned trainers. The V70R AWD is a Ferrari wearing family car clothes. I loved it, even though I thought it was crazy. One minute you're carrying pots and plants back from the garden centre, feeling all green and virtuous and awfully sensible; the next you're revving that turbocharged powerhouse of a motor around to the red line and racing away from the traffic lights like a kid driving your first sports car.

There is nothing sporty about the Subaru Forester, one of the first of the new-breed of off-roading estates. These offer some of the go-anywhere virtues of a Land Rover - by dint of their high ground clearance and four- wheel drive - but, being based on normal estates, they are more car-like on Tarmac. Volvo has just launched a rival (the V70 XC); BMW and Audi will soon have their own go-anywhere estates.

This proliferation has had one unusual casualty, however. Sales of the really big, commodious estates - which put carrying capacity before style - are evaporating. Volvo is to announce that its upcoming new big car, the S80 - successor to the 940 - won't be offered in estate form.

The traditional square-back substance-before-style Volvo estate is dead.

Huge carrying capacity, it seems, is the one thing estate car buyers no longer demand.