It's not the lowest mileage P1 GTR we've seen go up for sale, but it's the most expensive.
The McLaren P1 GTR is at the pinnacle of performance, it's one of the best cars ever produced, and there were only 45 of them at that. The GTR was quite different to the first McLaren P1, it was a dedicated track toy, a lighter, faster, sharper version of the base car. Of course, not too many owners would actually put the car on track and so they sought to have the car legally converted to be street legal. British outfit Lanzante Motorsport offered this conversion and they've done it to a few GTRs.
We saw one listed for over $7,000,000 a while back, which now seems like a bit of a rip off, as that one had been used. Another went up for sale with zero mileage on it, and that was listed for what looked to be a bargain in comparison at a shade over $4.500,000. The one you see here is an even better bargain with an asking price of a mere $3,581,907. While it's less used than the one in Italy, it has more mileage than the other, but it's basically delivery mileage, less than 160 miles. It's also arguably better looking in that simply awesome Cerulean Blue paint with a carbon black Alcantara interior.
To sweeten the deal even more, the guys at James Edition, where the McLaren is currently resting in a well-lit, climate controlled showroom, will throw in a complete race box that includes a track laptop, a bunch of additional spare parts and even a set of rain tires (hopefully on a set of extra wheels too) for when you feel like taking the P1 to the track, in the wet. That last item makes perfect sense with the car being registered in the United Kingdom, rain doesn't stop people doing what they need to do, it's just something that makes everything wet.