Six hundred and six takes it took, and if they had been forced to do a 607th it is probable, if not downright certain, that one of the film crew would have snapped and gone mad.

On the first 605 occasions something small, usually infuriatingly minute, went just slightly awry and the whole delicate arrangement was wrecked. A drop too much oil there, or here maybe one ball-bearing too many giving a fraction too much impetus to the movement. Whirr, creak, crash, the entire, card-house of consequences was a write-off and they had to start again.

Honda's latest television advertisement, a two-minute film called "Cog", is like a fine-lubricated line of dominoes. It begins with a transmission bearing which rolls into a synchro hub which in turn rolls into a gear wheel cog and plummets off a table on to a camshaft and pulley wheel. All the parts are from the new Honda Accord - £16,495 to you, guv'nor, or £6 million if you want to pay for the advertising campaign. And what an amazing ad campaign it is, too.

Back on Cog, things are still moving, in a what-happened-next manner redolent of "there was an old woman who swallowed a fly". With a ting and a ding of metal on metal, a thud of contact and the occasional thwock, plop and extended scraping sound, the viewer watches as individual, stripped-down parts of car roll into one another and set off more reactions.

Three valve stems roll down a sloped bonnet. An exhaust box is pushed with just enough energy into a rear suspension link which nudges a transmission selector arm which releases the brake pedal loaded with a small rubber brake grommit. Catapult! Boing! On goes the beautiful dance, everything intricately balanced and poised. Nothing must be even a sixteenth of an inch off course or the momentum will be lost.

At one point three tyres, amazingly, roll uphill. They do so because inside they have been weighted with bolts and screws which have been positioned with fingertip care so that the slightest kiss of kinetic energy pushes them over, onward and, yes, upward. During the pre-shoot set-ups, film assistants had to tiptoe round the set so as not to disturb the feather-sensitive superstructure of the arranged metalwork. The slightest tremor of an ill-judged hand could have undone hours of work.