It's reportedly a one-off commission for an extremely wealthy client.
Not long after we were given a sneak peek of the McLaren 570LT, the mighty P1 is now also getting the Longtail treatment. Except it isn't being developed by McLaren. Instead, the project has been handed over to Lanzante Motorsport, the same company that helped McLaren win the 24 Hours of Le Mans in 1995 with the F1 GTR. More recently, Lanzante converted the track-only McLaren P1 GTR to road-going LM spec, creating a spiritual successor to the F1 LM.
Details are scarce for now, but it goes without saying that this will be an even more extreme version of the P1 hybrid hypercar. A teaser photo released by Lanzante gives us a sneak preview of the P1 GT Longtail's front and hood with more vents at the top of the fenders, a larger front splitter and an even more aggressive aero package. We don't get to see a view of the back where the most significant changes will be, though. As the name suggests, Longtail McLarens feature longer, more aerodynamic rear sections to increase downforce, and are also significantly lighter. Clearly, the project is still in development because the photo shows a completely stripped cabin devoid of seats.
It also appears to be finished in the same shade of green as the 1997 McLaren F1 GT, a road-going version of the Longtail race car that was designed for the 1997 FIA GT Championship. Specifically, it appears to mimic the XP prototype that still belongs to McLaren. Only three F1 GTs were built in total. No specifications have been revealed, but if it's based on the P1 GTR we can expect it to use a hybrid setup combining a 3.8-liter twin-turbocharged V8 with an electric motor. With less weight, the P1 GT Longtail could exceed the GTR's 217 mph top speed. According to DriveTribe, the P1 GT Longtail is a rumored to be a one-off commission by a customer in the Middle East.
No word on when we can expect the final car to be revealed, but we wouldn't be surprised if it shows up at the Goodwood Festival of Speed next month.