An ultra-rare McLaren Sabre has come up for private sale, which is being facilitated by Barrett-Jackson. This unique model is just one of 15 units made specifically for the US market and benefits from hands-on development by McLaren Special Operations. The benefit of making this supercar a region-specific model is that the designers were not subjected to adhere to global homologation rules and only needed to focus on what was legal in the USA.

Using the Senna's chassis, the Sabre has been given a more distinctive look thanks to the addition of even wilder styling cues. Power is sourced from a 4.0-liter twin-turbo V8 that delivers 824 horsepower and 590 lb-ft of torque to the rear wheels.

The model that is on sale here is chassis number three and features predominately naked gloss carbon fiber panels. Contrast is provided by an eye-catching purple-and-blue pearlescent Pacific Colour Stream finish applied to the side pods. Napier Green paint used on the brake calipers adds another pop of color, while the center caps of the diamond-faced wheels are treated to more psychedelic paint. '03' and 'MSO' interwoven graphics feature on the front and rear side blades.

Inside the cabin, the Sabre is finished with Carbon Black Alcantara upholstery applied to sections of the carbon fiber bucket seats, doors, dashboard, and steering wheel. This is contrasted by Cerulean Blue and Mauvine stitching. Pacific Colour Stream detailing is fitted to the steering wheel and door struts while the MSO logo has been laser-etched into the accelerator pedal.

Considering that the Sabre is such a personalized product, it's quite a surprise to see it listed for sale just under a year after deliveries took place. Barrett-Jackson has included the original window sticker showing a price of $3,790,000 when new, but we'd bet that when you call to inquire, the asking price will be considerably higher. This car was probably bought and specced specifically to sell on later at a profit, which is a real pity when you consider that it debuted as the fastest two-seater McLaren ever (the F1 is still the all-out king). This is a car built to be driven hard, and it's brilliant around corners too, but with an expected asking price likely well over $4 million, it'll probably remain a garage queen for all time. What a pity.