We all see the headlines. We know that DJ Chris Evans paid £5.6 million for a Ferrari 250GT California, and that until then the record price paid at auction was for a Bugatti Royale at £5.5 million, back in 1987. But these prices are public domain. Behind the scenes there are even higher prices paid – and what of the cars that just won’t ever be sold? Museum cars, manufacturers’ cars, private collectors’cars that will simply be handed down as heirlooms… When a car is a one-off, or has unique history, it’s worth as much as someone will pay for it.

Over the following pages we give you the 25 cars that we view to be the most important (and therefore valuable) in the world. We drew up our list and asked experts around the globe to give us theirs – unusually, for a subject that stirs up such strong opinion, the lists came in remarkably similar. Note that the values we’ve assigned are purely estimates, based on our experts’ judgements and actual previous prices realised. And, while they may seem high, they’re nothing like the stratospheric prices paid in the art market.

You’ll notice that there are no modern Formula One cars in there, despite the fanatical following that, say, Senna and Schumacher attracted. That’s because, while F1 cars might seem desirable, anything from the 1980s onwards is not user-friendly. As Nick Mason pointed out, few car enthusiasts are fit enough to drive recent F1 cars, and fewer still want to employ 20 technicians every time the car is driven.

Some of our choices are obvious. Others represent a type of car that is obvious, but which specific example is the most important? It’s all down to provenance and originality. And if we’re talking provenance, it’s interesting to find that, worldwide, cars with Le Mans history head the desirability tables. Read on…

NEXT: No. 25 - Jim Clark's Lotus 49