A year ago, the name Flachbau RS surfaced in patent filings — and everyone started guessing whether Porsche was bringing the legendary slantnose back into series production. The answer turned out far more exclusive than any guess. The finished car is real, but it’s a single customer commission under the Sonderwunsch programme, built on a nearly new 911 GT2 RS of the 991.2 generation. Porsche, Manthey and related departments spent three years developing and testing it. One car. Three years. Remember that name.
The engine has nothing to do with it — and that’s arguably the biggest surprise. The 3.8-litre twin-turbo flat-six stays mechanically stock, just like a regular Weissach-package GT2 RS, and the base GT2 RS tops out at 340 km/h. All the attention went to the front end, which had to be redesigned from scratch for those low-slung fenders in the style of the racing Porsche 935/78: compact LED units, vented slats above the wheels, and even a reworked fuel-filler mechanism — the new fender shape simply wouldn’t fit the old one.
Even so, the Flachbau RS shed 31.6 kg compared with the donor car — and that’s despite the GT2 RS already being one of the lightest 911s in the lineup. Gone from the cabin are the infotainment system, speakers, sound insulation, floor coverings, and even wiring that no longer powered anything. Out back, a new adjustable wing grew in — structurally, it traces back to the 911 GT3 R rennsport. The payoff is serious: in its most aggressive setting at 340 km/h, the rear axle alone sees roughly 554 kg of downforce.
The historical nod here is anything but subtle. The nose shape traces back to the Porsche 935/78, nicknamed Moby Dick, and the road-going Flachbau of the 1980s became one of the rarest factory 911 variants ever built — just 948 units over the whole decade. Porsche already brought the 935 back once, in 2018: that time it built 77 track-only cars on GT2 RS running gear. But there won’t be a repeat run this time.
Because this car isn’t the start of a new series — it’s the end of one before it even began. Porsche is tying the registered Flachbau RS name to this single project alone; there’s no word of any volume or even limited-run follow-up. Last year’s question — “what will the new Flachbau look like?” — can be put to rest: this isn’t a new 911 trim level, it’s a demonstration of just how far the Sonderwunsch programme is now willing to go for a single customer.
