Manhart gets a hold of the BMW M4 CSL and turns it into the MH4 GTR II. The powertrain tuning pushes the twin-turbo 3.0-litre inline-six engine to an impressive 702 bhp (524 kilowatts) and 649 pound-feet (880 Newton-metres). For comparison, the model's stock output is 543 bhp (404 kW) and 479 lb-ft (649 Nm).

To achieve such significant gains, Manhart fits its MHtronik auxiliary control unit and a stainless steel exhaust that ends in four round pipes that each measure 110 millimetres (4.3 inches). Buyers can select a carbon or ceramic coating for them.

Gallery: Manhart MH4 GTR II (Basis BMW M4 CSL)

The MH4 GTR II also has a more aggressive stance. The suspension gets height-adjustable parts from H&R. It rides on 20-inch Forged+ 1 wheels from Yido Performance. They have a 15-spoke design, and customers can pick the finish. 

Manhart installs an 18-piece, carbon-fibre body kit to the M4 CSL. The parts include a large front splitter and canards on the nose's outer corners. The side sills extend outward from the body. The tail gains a prominent spoiler on the boot lid. The diffuser surrounds the prominent exhaust tips.

The interior gains a roll cage, and Schroth four-point racing harnesses attach to it. The company includes a helmet with the car.

Manhart also offers downpipes without catalytic converters or with 300-cell catalytic converters. However, these parts don't have TÜV approval for use in Germany, so they are for export customers only.

BMW debuted the M4 CSL in May 2022 at the Goodwood Festival of Speed. It's the quickest series-production model ever from the brand around the Nürburgring Nordschleife with a time of 7 minutes and 20.2 seconds.

BMW puts the M4 CSL on an extensive weight loss program. This includes making extensive use of carbon-fibre-reinforced plastic components, including the bonnet, roof, and boot lid. The standard M Carbon ceramic brakes shed 14.29 kilograms (31.5 pounds) over conventional stoppers.

BMW is making just 1,000 examples of the M4 CSL. In the United Kingdom, the model starts at £128,820.