Every August tens of thousands of car lovers, including chief executives and whole families that are involved in car collecting and racing, travel to Monterey in California for the Pebble Beach Concours d'Elegance. This is arguably the world's most spectacular annual gathering of automobiles. This year's highlight was a line up of 21 Ferrari 250 GTOs; these are the most valuable production cars in the world and the display was worth approximately $500 million in total. "It's really the most important concours in the world," says Mr Richard Charlesworth, who wears two hats at Bentley Motors: director of royal and VIP relations as well as head of the Bentley Heritage Collection. "Only at Pebble Beach can you find a billionaire in awe of a mechanic," he says. Here, we profile just some of the finest machines on show.