The Detroit Motor Show hasn't even started as this is written, but what do you think the gathering critics are talking about? Gloom and despondency about the fading demand for cars? Concern about the affordability of personal transport in future? Not a bit of it. The talk here is of how petrol has dropped abruptly in price from around $4 a gallon to $1.80 so that for some people who can afford new cars in America - and in a market this big that's many thousands - the SUV and the mammoth pick-up are right back on the buying agenda. The Ford F150 truck, for many years America's best-selling vehicle, looks like it might even become king of the hill all over again.

Which presents the US government with just about the thorniest of thorny problems. They've just bailed out the car industry with billions of taxpayers' money, right? To safeguard that money, and get the best, quickest possible return as they're duty-bound to do, they might just be forced to do exactly what much-criticised car industry bosses have been doing all these years: build cars the market will buy. Market-watchers are starting to wonder whether the much-discussed 'car czar', if and when appointed, will have to get right back to doing what the car industry was doing all along, and that's building a solid proportion of trucks and SUVs.

Oh, and by the way, in case you think the oil price is about head straight back up again and put an end to all this nonsense, people I've spoken to over here claim there's a solid body of US futures traders prepared to speculate that the price of a barrel of oil will stay south of $75, or half the scary level it hit last summer, until around 2013. It's an indisputable fact that the demand for efficient, economical cars is falling here, which is why Toyota took the radical step of cancelling, or at least postponing, the US Prius assembly plant it had formerly planned to build in the US.