Robbie Coltrane has been dreaming of this since the age of six - the chance to buy a vintage Cadillac and drive it across America (and, no doubt, get paid handsomely in the process). If the first episode of Meridian's COLTRANE IN A CADILLAC (8.30pm ITV) is anything to go by, his enthusiasm has not dulled his wit. In the warehouse of his dreams - filled with the world's largest private collection of vintage Caddies - he strikes up a rousing chorus of 'I'm in Heaven'. Driving around Hollywood like a child with a new toy, he calls out to random passers- by: 'George, loved the picture', 'Maurice, get outta this town'. As he follows the example of the past master in arcane Americana, Jonathan Ross, he bumps into local eccentrics at every steet corner. After leaving Las Vegas, 'the capital of polyester decadence', considerably out of pocket and crossing the badlands of Utah, he ends by predicting the reaction of the 'quality press': 'Whilst it might be some people's idea of ideal television to watch the rather enormous Mr Coltrane driving an old banger across the salt flats, I found myself getting up to make a cup of tea after only 10 minutes'. Well, I didn't.