Monterey has increasingly become a showcase for Porsche’s most unusual factory projects. In 2024, the company brought Luca Trazzi’s Otto Yellow 993-generation 911 Speedster, a body style it had never series-produced for that generation, to The Quail, while a one-off Dani Blue 911 S/T appeared nearby at Porsche’s Monterey headquarters. Last year, Roger Penske’s street-legal 963 RSP made its first public appearance on American soil during Monterey Car Week. This year, it is the Porsche 911 Flachbau RS that continues that tradition.
When Porsche filed to protect the Flachbau and Flachbau RS names in May 2025, it looked like groundwork for a production slantnose revival. The name has now surfaced on this road-legal factory one-off built from a like-new 2018 911 GT2 RS with Weissach Package.
The original Flachbau ran from 1982 to 1989, with 948 examples sold. Grant Larson, who penned the modern 935 tribute that Porsche unveiled in 2018, led the design of the Flachbau RS. Porsche built all 77 of those 991-generation 935s as track-only cars. Lanzante later converted two for road use, but the Flachbau RS seen here is engineered by Porsche itself as a road-legal factory one-off.
Sonderwunsch, Style Porsche, Weissach development engineers, Porsche Motorsport, and Manthey spent almost three years on the project. The 991-generation GT2 RS that this car is based on is a model that is fast becoming a serious modern collectible, as confirmed by duPont REGISTRY Live results. The owner of this particular example requested a Flachbau silhouette and a rear wing inspired by the 911 GT3 R Rennsport, with the stock twin-turbocharged powertrain staying untouched.
“The new Flachbau RS is a modern, fitting reinterpretation of the iconic 935 Moby Dick design. In addition to the flatter front wings, a key feature is the staggered headlight arrangement with very narrow LED units.” - Grant Larson, designer
It is that distinctive Flachbau or Flatnose (Slantnose) front-end that is the highlight here, and a new headlight setup had to be engineered to achieve the flatter nose. The standard round units have been replaced with three LED elements arranged in tiers. The low- and high-beam units each measure just under 1.6 inches tall, while the daytime running lights come in under an inch. The front wings sit lower and carry slatted louvers that vent pressure from the wheel arches, requiring Porsche to redesign the fuel-filler flap and its mechanism.
The car is finished in Grand Prix White, a color introduced on the 911 in 1974 and recreated using a historic example from the Porsche AG collection as a reference. Black exposed carbon fiber forms the center stripe and U-shaped nose graphic, the latter a direct reference to the Martini-liveried 935/78.
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The rear wing sits roughly two inches higher than the GT3 R rennsport wing that inspired it and can be manually locked into three positions. At 211 mph in the High Downforce setting, it generates 1,221 pounds of downforce on the rear axle. Porsche says that the wing adjustment system and its position markings are protected by patent.
Inside, the cabin has been stripped much like a racing car. Porsche removed the PCM system, the entire audio setup, most of the sound-deadening material, and even individual wires that were no longer needed. The newly laid wiring harness remains exposed beneath protective sheathing. Altogether, the changes save roughly 70 pounds from a car already engineered around weight reduction.
Porsche built three test vehicles for lighting, wind-tunnel, and real-world validation. The program included repeated runs at Mendig airfield, 50 laps of the Nordschleife, and endurance testing at Weissach that simulated roughly 93,000 miles of customer use on the rear wing. The trademark filings suggested a new model. What Porsche delivered instead is rarer: one customer’s vision, three years of factory development, and a road-legal bridge between Moby Dick and the modern GT2 RS.
The Flachbau RS may not be the production revival the trademark filings appeared to promise, but it is arguably just as interesting. With Porsche yet to reveal a 992-generation GT2 RS, this one-off gives the 991-generation flagship an unexpected and spectacular encore.
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Images: Porsche, Charles Bradley
