Some of us were still in the bus heading for the Cobo Arena for the opening of the Detroit motor show when we heard the bombshell Porsche news, that in future they'd be co-operating with Bentley over at least one sports car project.

Suddenly lights began to go on.

First, Porsche seem to have made an official policy of doing something amazing at the very beginning of a motor show - as they did at Geneva last year by unveiling the 918 Spyder - so everyone else's news looks a bit shabby.

Now the sense of Wolfgang Durheimer moving to replace Franz Josef Paefgen at Bentley made sense. Suddenly Bentley's prospects (they make good cars but their post recession sales aren't recovering too well) looked distinctly brighter.

And all this made the Detroit show look like the place to be. Last year's was nearly cancelled. This year shows that the wake is definitely over. New product is everywhere, much of it with a European cast.

Electric cars and hybrids look more believable. Ford has overtaken Toyota as America's No2 manufacturer. GM has just come successfully out of the biggest company flotation in history. Chrysler sales are usefully up and they have the advantage of the remarkable Sergio Marchionne at the helm.

Optimism is more than guarded, yet we're spared the money-wasting and more than slightly ridiculous sight of company execs doing elaborate presentations, often in costume. This could be a good day.