Hamish McRae: Are you sitting comfortably?

Watching parents un-loading their children into the local primary school the other day, it struck me that for many drivers the chief quality designers ought to seek to engineer into cars is calm.

Watching parents un-loading their children into the local primary school the other day, it struck me that for many drivers the chief quality designers ought to seek to engineer into cars is calm. Yes, people want style and space; they want reliability and safety; and they want cars that are fun to drive. But calm - that is the bit of most city dwellers' lives that is most elusive.

But how - aside from not having primary school children in the back of the car and not having cyclists shout at you for no reason?

Some years ago I found myself in Tokyo talking to the head of Nissan's design team. I asked him what, in the next 20 years, would be his greatest challenge? "Making a car a pleasant place to be in, when stuck in a traffic jam," he replied.

Driving a variety of cars over the past year or so, I think I understand his point. Design gurus talk about cars being extensions of living rooms or indeed bedrooms, but I think the answer is more practical. There are a number of detailed things that good designers can do to cars to make them much calmer places in which to be. Here are my top five.

First must be silence in traffic. An engine idling when stopped in traffic is an engine tut-tutting: "We really ought to be on the way, I'm ready but I can't do anything until this stuff clears". The eerie calm of the Toyota Prius, the petrol-electric hybrid, is because when it is stopped the engine cuts out. You are left with just the faint hiss of the all-electric air-conditioning. If you are just edging forward in heavy traffic, the virtually silent electric engine does the business. No conventional petrol engine can compete.

Two, the interior has to feel classy. One of the great puzzles of automotive design is the contrast between the quality of the stuff you don't see and the quality of the stuff you do. Who cares about the intricacies of the floor-plan, which cost £200 million to develop, when the seats are tacky and the dashboard is covered in vinyl? It does not matter whether the style is traditional or avant-guard. That will always be a personal preference - my own plea would simply be to ask designers not to be too clever or self-indulgent. What matters is the quality. You don't want bits of plastic coming off in your hand.

Three, seats have to be comfortable. Elementary, you might think but actually there is a vast range of quality. A few years ago all French cars had squashy seats that were supposedly bad for you but felt delicious, while German ones were hard and horrid but good for the back. The new norm is for seats to be a compromise between the two but some manage the compromise better than others.

Four, the tactile feel of the controls has to give a sense that the machinery is well-engineered. Good engineering is calming, bad engineering irritating. So you want electric switches that resist you, then flip over silently. You want power-steering that is tuned to the car's speed, giving full assistance when parking and more feel on the road. You want power to come on progressively and smoothly.

Finally, you want the right relationship between seat height, windscreen setting, general visibility (fat front pillars must surely be a safety hazard), the mirrors and the various controls. This is not fancy ergonomics; just common sense. If you can't see, or have nowhere to put your foot when it is off the clutch pedal, you won't feel very calm.

None of the above would make the day-to-day driving experience perfect. But they would make it better, more fulfilling - and I suspect make people drive better too.