It would, of course, be unreasonable to expect such consistency from cars. They are made up of 15,000 parts and some of them are made by people who are French. So, naturally, there will be mistakes from time to time.

But these days, for the most part, cars are staggeringly reliable. Tyres are able to run over broken bottles without detonating. Onboard computers get shaken, boiled and rattled around and still continue to function. Honda, for example, has made 15m VTEC units over the years and has never had a single warranty claim on any of them. That’s a Marlboro-like consistency.

But despite the car makers’ ability to build products to a fantastically high standard, I’m always amazed by some of the design faults that make it through the testing and development phase. The seatbelts in my Mercedes, for instance, are almost impossible to fasten. Did the boss not notice this, in which case he is an idiot? Or did he think, like an internet service provider, that not quite good enough will do?

Even if we take the Range Rover V8 diesel, which can do more things to a higher standard than just about any other car on the road, we find a wiper system that collects dirt from the car in front and smears it all over the windscreen so you can’t see where you’re going.

And now we arrive at the BMW 330d. In many ways, this is a perfect car. Anonymously styled for maximum anticock inoffensiveness, it’s the right size and it’s fitted with a diesel engine of unparalleled smoothness. You can find more power elsewhere, and more economy. But for a combination, with almost none of the tingling you normally get from a coal burner, this big six is the tip of the arrowhead.

And now that our friends with the Oakley sunglasses and the big Breitlings are all in Audis, BMWs are generally driven by enthusiastic drivers who like the balance of a rear-wheel-drive set-up, and the steering feel; people who understand that the stopping distance at 80mph is not 4in and drop back from your rear end accordingly.

The best bit of the 330d, though, is not the engine or the way it drives; it’s the suspension, which manages to be firm and comfortable at the same time. No other car maker can do this.

And yet, here in this wonderful package we find a sat nav screen made up of blues and greys. It’s all very tasteful but you can’t read it. Ever. And then there’s the headlamp dip switch, which works like the lever in a railway signal box.

But worst of all is the torque. Put your foot down to pull smartly out of a side turning and all you get is an ear-splitting screech as the tyres leave big black lines down the road. On gravel, you just dig a big hole, no matter how delicate you are with the throttle, and go nowhere.

It’s the little things, then, that spoil the BMW. It’s the little things that spoil everything. Like my iPhone, which was brilliant except that it didn’t work in the rain. Or the Sony Ericsson I replaced it with, which doesn’t work at all. Nothing does really. It’s annoying.

THE CLARKSOMETER

BMW 330d M Sport

Clarkson’s Verdict Could drive you to distraction
ENGINE 2993cc, six cylinders
POWER 245bhp @ 4000rpm
TORQUE 384 lb ft @ 1750rpm
TRANSMISSION Six-speed manual
FUEL 49.6mpg (combined) 152g/km
ACCELERATION 0-62mph: 6.1sec
TOP SPEED 155mph
PRICE £33,165
ROAD TAX BAND D (£145 a year)
RELEASE DATE On sale now

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