Porsche 911 Flachbau RS Is a Modern-Day Moby Dick

• What's new: Porsche's Sonderwunsch division has once again revealed a one-off special edition at Monterey Car Week, this time inspired by the legendary 935/78 race car.
• Why it matters: Serious work was done to a 911 GT2 RS donor car to pay homage to the road-going slant nose Flachblau.
• Edmunds says: A couple million dollars for a rebodied 911 GT2 RS is a steep ask, but how else do you say your special Porsche is literally made to order?

The work is thorough. Being rear-engined, the 911 has its fuel cap up front, and the reprofiling of front arches forced a redesign of the flap itself. Those headlights? Less than 2 inches tall, while the separate daytime running lamps (DRLs) are under an inch. That hood might be the same, but it flips the stripe pattern of the standard car.

Around back, the donor car DNA is clearer — at least below the hip line. This RS swaps out the standard enormous wing for one even taller, now mounted on dramatic S-shaped struts. Porsche says it was inspired by the current 911 GT3 R race car. Like the GT2 RS, the wing has three manually adjustable positions: In both the low and high downforce settings, the Flachbau produces fractionally more downforce than a GT2 RS with the Manthey Kit. (We're talking 2% and 3%, respectively.) The "OE3 SV" badging on the end plates is a combination of the internal code designation (OE3) and letters chosen by the client (SV).

Speaking of Manthey, the Porsche motorsport team was also part of the Flachbau RS development process. The car uses the full underbody structure (and rear wheel aero discs) of the Manthey Kit, which, when combined with the rest of the package, should make this the highest-downforce 911 of the 991 generation. The exterior paint is a simple Grand Prix white, a 1974 Porsche 911 color. Porsche even pulled out a historic model from its own museum collection to ensure an exact match.

The Flachbau takes a distinct race-car bent inside. The cabin is pared back to the extreme: Gone are the infotainment and entire audio system, while much of the sound deadening and carpet have been scraped away, leaving exposed metal. At least there's a leather-lined cubby where the screen used to be. Porsche (and the owner) have been so obsessive about weight saving that the new wiring harness isn't even fully covered, and individual wires were removed to shave every gram.

The end result? Just shy of 70 pounds in further reductions over the already light GT2 RS with Weissach Package, which tipped the scales at 3,201 pounds. The required safety kit, including a warning triangle and towing eye, are now stored in a dedicated box in the frunk; removing them for a track day ditches another 11.9 pounds.

While multiple examples of the Flachbau RS were built for validation and testing (including crash tests), and Porsche took the special model to the Nürburgring, there is no official lap time for it.

More on Sonderwunsch

Porsche Sonderwunsch costs vary on a project-by-project basis. While it's unlikely we'll ever know the full cost of the Flachbau RS program, we know it's well into the seven-figure range. An early concept phase runs 18 months and starts from 150,000 euros; the eventual completion can run from 2 million to as much as 15 million euros, according to Porsche. Timing naturally varies as well, with Porsche saying "more than one, less than five years" as a general rule for one-off projects.

This is only for the most extensive projects like Flachbau RS and 993 Speedster. Sonderwunsch also handles two other categories of projects. Factory commissions include bespoke and inspiration models, including the recent "Toy Story 5," while factory recommissions encompass enhanced factory restorations of previous models.

With one-off programs such as Flachbau RS, the client becomes a project manager, complete with an employee ID card. It isn't just for show: As Sonderwunsch head Claas Hoops explains, clients gain clearance access that even regular employees may not have.