Team Penske is the outfit that runs the Porsche 963 in both IMSA and WEC, so it’s just about right that he got nominated as the customer for the car. Now, the idea itself didn’t come from the 88-year-old billionaire team owner, but from Timo Resch, president and CEO of Porsche Cars North America who pitched it as a tribute to the Count Rossi 917—a racecar turned road legal around 50 years ago.

The design brief for the 963 RSP is simple: stay close to the race car as possible, while making it road legal.

As it turns out, the challenge started as soon as Porsche considered the paint job. The carbon fiber and Kevlar body work is so thin in places that it had to be altered to take on the paint-to-sample Martini Silver colorway complete with a triple-layer lacquer.

To make it road legal, it also gained new fender vents, a reworked rear wing minus the blanking plates, mounting points for the number plates, a horn, and tweaks to the software for the head- and taillights to work as turn signals. It rides on rain-spec 18-inch tires (you don’t want to be running slicks here) as well. Finally, an enamel Porsche crest replaces the graphic applied to the 963 LMDh.

The 800-volt hybrid powertrain and 7-speed Xtrac sequential gearbox have been carried over, but with a couple of modifications. The rear-mounted electric motor and generator were remapped to deliver power more smoothly (the output of 50 kW or 68 horsepower has been retained), while the mid-mounted, twin-turbo 4.6-liter V8, which is good for around 680 horsepower, has been reconfigured to run on standard pump gas.

Engineers have increased the ground clearance, and chose the softer available setting for the adjustable Multimatic DSSV dampers.

The modifications are enough to earn the 963 RSP special permission from the French government to be driven on public roads. It’s not fully homologated, but it is road legal “under special circumstances and in accordance with local requirements.”

Inside, the Porsche 963 RSP gets a cabin wrapped in tan leather and Alcantara. The carbon air-conditioned seats come straight from the racecar, but are softened with handcrafted upholstery, fixed headrests, and actual padding. The footwells and roof liner are trimmed in Alcantara too, while the steering wheel and door panels are leather-wrapped. The air vents, meanwhile, are shaped like the fan blades from the Porsche 917’s engine. There’s also a detachable 3D-printed cup holder and a small trimmed panel next to the driver’s seat that can fit a laptop, helmet, or the removable steering wheel. Finally, there is an alloy plaque on the door with the vehicle’s chassis number alongside the date and location of construction.

The one-off is finished with a custom-painted helmet and a set of tools with leather-wrapped handles.

Porsche hasn’t said how much it cost to build the 963 RSP, but it’s safe to assume that it’s hellaexpensive. Not that it matters, since Porsche won’t be making another. For now, the one-off is on display at the Circuit de la Sarthe for the 24 Hours of Le Mans. After the race, it’s heading back to the Porsche Museum in Stuttgart for a short stay before making its way to the Goodwood Festival of Speed, where it will appear alongside the original 917.