Porsche Sonderwunsch Unveils One-Off GT2 RS 'Flachbau RS' Homage to Moby Dick

Key points

• The Flachbau RS is a one-off Sonderwunsch creation based on a 2018 911 GT2 RS, designed to replicate the silhouette of the 1978 935/78 'Moby Dick' race car while maintaining road legality.
• The powertrain remains unchanged from the donor car, featuring a 3.8-liter twin-turbo flat-six engine with 700 horsepower and 553 lb-ft of torque, as requested by the client.
• The car weighs 70 pounds (31.6 kg) less than the standard GT2 RS due to the removal of infotainment, audio systems, sound insulation, and interior trim, leaving exposed painted metal and carbon fiber.
• A new rear wing with three adjustable positions generates up to 1,221 pounds of downforce on the rear axle at the car's top speed of 211 mph, inspired by the 911 GT3 R Rennsport.
• The vehicle underwent extensive validation, including 50 laps at the Nürburgring Nordschleife, where it recorded lap times under seven minutes, and was tested in wind tunnels and on high-speed tracks.

Background

Porsche’s Sonderwunsch program, relaunched in 2021, creates bespoke one-off vehicles for high-net-worth clients, following previous projects like the 993 Speedster and 997 Classic Club Coupe. The Flachbau RS continues this trend of extreme customization, building on the legacy of the original 1980s road-going Flachbau and the 2018 935 concept car. This release follows recent Porsche developments, including the reintroduction of the manual 911 Carrera S and the unveiling of the RUF Ehra, highlighting a broader industry interest in driver-focused, heritage-inspired performance vehicles.

How outlets are covering it

The Drive emphasizes the car’s status as the most ambitious Sonderwunsch project yet, highlighting the involvement of designer Grant Larson and the extensive engineering effort required to maintain road legality while achieving extreme performance. Porsche’s official release focuses on the technical validation process, detailing the 1,000 km of endurance testing at the Nürburgring and the collaboration between Porsche, Manthey, and Weissach. Motor1 highlights the aesthetic changes, particularly the new vertical LED headlights and the inverted stripe pattern compared to the standard GT2 RS, while noting the car’s display at The Quail. Top Gear notes the practical constraints of road legality, such as the inability to use pop-up headlights, and praises the car’s stability at high speeds as confirmed by test driver Lars Kern. All sources agree on the core specifications but differ in emphasis, with Porsche focusing on engineering rigor, The Drive on the program’s evolution, and Motor1 on visual design details.

Why it matters

The Flachbau RS demonstrates the upper limits of Porsche’s customization capabilities and the demand for heritage-inspired, high-performance one-off vehicles among wealthy collectors. It showcases how modern engineering can reinterpret classic race car designs while meeting contemporary safety and legal standards, setting a new benchmark for bespoke automotive projects.

What to watch

The Flachbau RS will be displayed at The Quail, A Motorsports Gathering, in Monterey. Porsche has stated that while they will evaluate similar requests, the one-off nature of the program means no exact replicas will be produced. The car remains in the possession of its anonymous European client.