On the scale of the US, Detroit is not so far from New York. It’s just less than 500 miles and around 90 minutes by plane.

But last week I hopped between the two places and was struck the extreme contrast between post-crunch middle America and the country’s most internationally-minded city.

Detroit was always to rough, tough, industrial city, but the extent to which it was finally hammered into the ground by the global financial crisis is sobering.

General Motors and Chrysler were bankrupted mainly because they were producing domestic models that were anywhere from plain uncompetitive to completely out of date.

The state of the domestic US car industry was brought home to me by a visit last week to GM’s Hamtramck factory, the new home of the new Chevy Volt range-extender electric car.

Built in 1985, it contains 3.6m sq ft of space under one roof and a capacity of 400,000 vehicles per year.

In 2007 it was only managing 120,000 units. In 2009 it was down to just 35,000. Then again, the plant was building the V8-engined Caddy DTS and the 5.1m long Buick Lucerne, both proper, old school, US luxury saloons. Models that were serving a shrinking market.