The final 12 versions of the open-top 600LT take inspiration from a venomous spider.

Retirement is almost always cause for celebration and commemoration. To wit: the McLaren 600LT Spider Segestria Borealis, an extremely rare creation by McLaren Special Operations that takes its inspiration from the sinister segestria florentina arachnid. Nicknamed the “spider spider” by MSO, the design firm will apply the Segestria Borealis treatment to all 12 final examples of the open-top 600LT. On sale now, the final-edition 600LT Spider carries a price of $275,500.

MSO starts with shimmering Borealis Black exterior paint, which pops in the light with green, purple, and dark red undertones, just like the iridescent black coloring of the venomous spider. Over that paint goes a pair of Napier Green stripes running from nose to tail over the top of the car, recalling the spider’s chelicera “fangs.” Napier Green finds its way onto the supercar's brake calipers and pinstripes on the rear diffuser, front fenders, and side skirts. A motif that matches the segestria florentina’s chaotic, tube-shaped web appears on the spoiler and side mirrors.

The McLaren Segestria Borealis also includes the MSO Clubsport pack, adding lightweight titanium wheel bolts, gloss-finished carbon fiber front fender louvers, lightweight carbon fiber racing seats, and carbon fiber interior accents to the mix.

2020 McLaren 600LT Spider Segestria Borealis

Speaking of the interior, MSO gave it many of the exterior’s design themes. The black, Alcantara-trimmed bucket seats get bright green stitching and embroidered accents that match the irregular web pattern on the exterior. The Alcantara wheel’s 12-o’clock stripe is the same electrifying color, as are the carpet bindings.

In addition to the Clubsport package, the 600LT Segestria Borealis includes an upgraded Bowers & Wilkins 12-speaker audio system, rear parking sensors, a front axle lift system, and a McLaren Track Telemetry data recorder. Otherwise, it’s standard 600LT Spider fare: a 3.8-liter twin-turbo V8 boasting 592 horsepower (441 kilowatts) and 457 pound-feet (620 newton-meters), running power to the ground through a seven-speed gearbox. Acceleration to 62 mph (100 km/h) happens in 2.8 seconds, and downforce-generating bodywork helps keep the 600LT Spider glued to the road, even at speed.

Gallery: 2020 McLaren 600LT Spider Segestria Borealis