The McLaren P1 is only getting more desirable with age. When it first launched five years ago, the hybrid hypercar would set you back a cool $1.15 million. Only 375 models were produced, so they're also getting increasingly hard to get hold of. Browse through the classifieds, and there's a chance you may come across a listing by Tom Hartley Jnr. based in the UK. At first glance, the hypercar for sale looks like an ordinary McLaren P1, but it's an even rarer and more special example.

Why? Because it's one of just 14 'Experimental Prototypes' of the P1 that were built before the production version launched in 2013. Each one was rigorously tested in some of the world's harshest conditions, from the Death Valley to the Arctic Circle. Prior to the launch of the P1, these prototypes were handed over to influencers such as Jensen Button and Jay Leno to help publicize the hybrid hypercar ahead of its debut at the 2013 Geneva Motor Show. Out of the 14 prototypes, many didn't service as they were used for crash testing. This particular prototype, however, was utilized for the gearbox and Bosch injection development.

It was then later used as the GTR show car at the Geneva and New York Motor shows before being stripped back to its carbon fibre Monocage and rebuilt to the same specification as the final production car. Everything from the bodywork to the engine has been rebuilt around the original prototype chassis. The car is finished in McLaren's signature orange paint and has "XP05" etched on the rear quarter panel to distinguish it from the production model, as well as XP stitching in the headrests. Like the production model, it's powered by a 3.8-liter twin-turbo V8 hybrid that delivers 903 horsepower. The rare P1 prototype has only had one owner since it was new, and has clocked up 300 miles.

No price has been listed, but McLaren P1s typically command over $2 million, so a rare prototype could potentially cost more than that.