Hennessey has added a manual transmission to its Venom F5 hypercar, creating in the process the world's most powerful manual-equipped car.

The manual is paired with the Venom F5 Roadster body style in a distinct model known as the Venom F5-M Roadster, and just 12 will be built. The price for one is $2.65 million, and all build slots are already claimed, according to Hennessey.

The manual transmission is a 6-speed with a classic gated shifter, and installing it meant a remapping of the engine was required to pair it with the new gear ratios. One of the key changes was to introduce more graduated power delivery to prevent the tires from breaking loose in the lower gears.

Like all Venom F5s, the Venom F5 Roadster is powered by a twin-turbocharged 6.6-liter V-8 that generates a peak of 1,542 hp on pump gas (91 octane) and as much as 1,817 hp when running on E85. Hennessey hasn't said what the 0-60 mph time is, but Venom F5s with the standard 7-speed automated manual transmission will run from 0-62 mph in a claimed 2.6 seconds and potentially top out at more than 300 mph. Hennessey plans to make a top speed run eventually.

The Venom F5-M Roadster also stands out with some unique design details including its central stabilizing fine, a model-specific stripe package, and a new center console incorporating the gear shift lever as well as jet-fighter-inspired toggle switches for the windows.

Buyers can also choose from a full range of available colors and various carbon-fiber accents to further personalize the car.

While the Venom F5-M Roadster is no longer available, Hennessey said build slots for other Venom F5 models are still available. Other models include the standard Venom F5 and Venom F5 Roadster, plus the track-focused Venom F5 Revolution and Venom F5 Revolution Roadster.