What should family cars offer? If you said they must be spacious, practical, versatile and as inexpensive as possible, you would be right. But not all manufacturers would agree: on the evidence of the cars they currently serve up, they obviously believe that family cars should be stylish sex symbols aimed at image-conscious trendies who don't give a fig for practical, rational values.

The daft car ads give us a clue to the car makers misguided priorities (Volvos that go faster than Ferraris, Mondeos that make your heart beat faster, naked supermodels). Even more revealing is the cars they serve up. Cars nowadays are designed to look sexy and stylish first, and hang many practical values. Interiors are cramped, even in supposed family cars, with rear seat room being especially derisory.

I remember pointing out as much to a Rover high-up some years ago (after Rover had reduced the rear seat room of the Metro) and he told me that people don't travel in back seats any more, so it didn't really matter. Rover's change, from the maker of the world's most space-efficient cars (in its Austin/Morris days) to a manufacturer of cars that supposedly put style before practicality (but still fail to be stylish) is perhaps the most extreme example.

My dad owned an Austin 1800 in the late 1960s. It was a supremely roomy and comfortable car, designed from the inside out. In other words, it was designed, first and foremost, with people in mind. Everything else was of secondary importance. Nowadays, cars are apparently designed from the outside in. Style sells, so the fact that back seats usually have insufficient headroom for tall men, or insufficient leg or knee room, or preposterously short cushions, or that back benchers often have to sit in heavily reclined chairs is deemed of secondary importance.

Today, there is no family saloon which offers outstanding rear room. None is anywhere near as space efficient as my dad's marvellous old Austin.

Ten years ago I owned a classic car I'd long wanted - a 1954 Citroen Light 15, sometimes known as the Traction Avant. It is one of the most beautiful and technically intriguing cars ever made (the reasons I wanted one), yet it was also supremely roomy and comfortable in the rear. It was comfortable because, as with my dad's old Austin, rear seat occupants sat upright in luxurious, large chairs, such as you would expect in a family lounge. I remember trying one of the then-new Ford Mondeos, towards the end of my stewardship of that fine old Citroen. I was amazed to find the rear of the Mondeo profoundly less comfortable, partly because of the much lower roof, necessitating a more reclined riding position. And yet the two cars were almost the same length, and covered much the same area of road occupation. Of course the Mondeo was faster, more refined, more fuel frugal and safer - all evidence of the huge strides made in recent car engineering. Yet comfort - surely the primary role of any family car - had been sacrificed in the interests of sporty styling and "emotional" appeal.

The irony is that truly great cars offer both function and form - the latter flowing from the former. The Mini was never really styled. It looked the way it did because that was the most practical way to clothe a small car that was designed to seat four, and yet be as small as possible. It was a great design, not a pretentious style statement. The same could be said of my old Citroen, of the 2CV, of the first Range Rover, of the Fiat Tipo and of a variety of old Renaults. Car makers would do well to learn from them.