Like many people since the dawn of that ultimate displacement activity known as YouTube, I thought I’d seen all the good motor-racing footage there was to see. Not so. As a result of a new DVD called ‘Can-Am, The Speed Odyssey’, I am now £23 lighter in the pocket and several hours behind with my work.

As you will have guessed, it tells the story of the Canadian-American Challenge Cup’s halcyon days, from its inception in 1966 to its effective demise under a 1100bhp Porsche steamroller at the end of 1973. Narrated by Sam Posey, who is almost as gifted a broadcaster as he was a racing driver, the DVD provides a unique insight into racing not just from another time, but seemingly another planet.

Because you could have written the entire Rule book on the back of a packet of Rizlas, the cars taking part were perhaps the wildest ever to assemble on a grid together and, despite the fact that the vast majority of them were powered by what was even then resolutely old-school Detroit big-banger V8s, they had no problem lapping tracks faster than the fastest F1 cars of the day.

Unsurprisingly, Can-Am attracted the best drivers – Bruce McLaren, Denny Hulme, Mark Donohue, Jackie Stewart, John Surtees and Jody Scheckter – and the greatest manufacturers, from the orange McLarens and black Shadows to white Chaparrals and blue Porsches. To see them in all their splendour thundering around North America is something not to be missed. Everything about Can-Am was big: big cars, big names, big speeds, big accidents…

The DVD is far from perfect: some of the camerawork is pretty amateurish, the quality is patchy in places and, while some seasons are covered in great detail, others get little more than a passing nod. Lack of available footage I guess. Even so, having watched it once, my first instinct was to watch it again, which is always a good sign.

How good is it? In my reasonable collection of racing videos and DVDs, it’s in the top five for sure.

One final aside: congratulations to David Donohue for winning the Daytona 24-hour at the weekend. Exactly 40 years ago, his father Mark won the race in a Lola T70 MkIIIB and would go on to become the greatest Can-Am driver of them all. Mark died after an accident in practice for the 1975 Austrian Grand Prix when David was just eight but, if there is a great Can-Am track in the sky, right now there must be one proud dad looking down from it.