Two decades ago, Mercedes-Benz and McLaren teamed up for a unique supercar project.

The resulting Mercedes-Benz SLR McLaren was the road-car side project of the two companies' Formula 1 racing partnership. The partnership had produced a Constructors' Championship, plus two Drivers' Championships for Mika Häkkinen by the time the SLR was unveiled at the 2003 Frankfurt auto show.

According to McLaren, the goal was to capitalize on that success with a road car. Mercedes showed a concept car called the SLR Vision at the 1999 Detroit auto show, and McLaren confirmed plans for a production version codenamed Project 7 at the British Grand Prix later that year.

While McLaren had built the F1 supercar, it was effectively starting from scratch with the SLR. A team of ex-F1 mechanics and automotive engineers, including Gordon Murray, were responsible for developing the car, which was also the first to be produced at the company's McLaren Technology Center headquarters in Woking, England.

Mercedes-Benz SLR McLaren 20th anniversary celebration at McLaren Technology Center

Mercedes-Benz SLR McLaren 20th anniversary celebration at McLaren Technology Center

The SLR McLaren had the typical ingredients of a supercar, including a carbon-fiber monocoque chassis and a supercharged 5.5-liter V-8 producing 617 hp. That power was routed to the rear wheels through a 5-speed automatic transmission, allowing for an estimated 0-62 mph time of 3.8 seconds and a top speed of 208 mph.

Instead of the fashionable mid-engine configuration, however, the SLR McLaren had the long-hooded, front-engine shape of the SLR Vision concept, also referencing the original Mercedes SLR race cars of the 1950s. In addition to the initial coupe, an SLR Roadster convertible was built, along with a 722 GT track car and a Stirling Moss speedster honoring the late racing legend.

Production ended in 2009, along with the partnership between McLaren and Mercedes (Mercedes went on to form its own F1 team), but McLaren has continued to offer upgrades for the SLR fleet. In 2010, McLaren Special Operations (MSO) launched a McLaren Edition package with upgraded aerodynamics, tweaks to the suspension and power steering assist, and a limited run of 25 units. In 2019, a series of SLR by MSO upgrades were introduced, ranging from new aero elements to quilted leather upholstery.

In May 2023, McLaren delivered the first SLR with a new High Downforce Kit inspired by the 722 GT track car. The kit widens the track by 2.3 inches front and rear, and includes fender flares and a rear spoiler inspired by the one used on the McLaren F1 GTR. The production run of 12 units has already sold out.