David Prosser: Cars are the sum of all their parts

Outlook The wonderful Honda advertising campaign, in which automotive components combine to produce an extended domino effect, made the point very effectively: the 21st century car is a complicated beast with a myriad of working parts that each plays a crucial role in driving the thing forward (or backward sometimes).

It is that complexity, however, that is now causing Honda and its fellow Japanese auto-makers such difficulty. Like Nissan and Toyota before it, Honda said yesterday that it would have to constrainproduction in the UK because the tragedy of the earthquake and tsunami back home has lead to shortages of some components. Similar curbs on production are already taking place in Japanese car companies' factories all around the world.

Should the supply chain problems continue for an extended period, it is possible Honda, Nissan and Toyota will lose sales to rival car manufacturers. But it will be interesting to see if those rivals are also hit by the production problems in Japan to the same extent.

The modern car has around 20,000 components and almost every manufacturer relies on Japanese companies for some of them. Shortages may therefore soon begin to force other car companies to rein in production too.