The M-Class was the first luxury SUV to feature stability control, a system designed to detect loss of control and instantaneously intervene with selective braking to bring the vehicle back on its intended course. This system is now hailed by safety experts, and studies have shown stability control and systems like it are capable of reducing single vehicle crashes by up to 30 percent. Furthermore, the M-Class boasted front- and side-impact airbags with advanced occupant detection for the front passenger seat, which, combined with Mercedes' legendary safety structure, earned the M-Class the highest marks in insurance industry crash tests.
Aroad test on the BBC programme Top Gear revealed that the presenter, Jeremy Clarkson, could put his fingers into the gap below the rear lights and above the rear bumper. This improved over the years, especially after a mild facelift for 2002. However, owners are often unhappy with the car's quality — for example, the car was placed last out of 142 cars in the Top Gear Motoring Survey 2004. DaimlerChrysler spent US$600 million on improvements at the Alabama factory before launching the second-generation ML in 2005.
Before the vehicle was launched, Mercedes-Benz allowed the producers to use two pre-production M-Class SUVs in the film The Lost World: Jurassic Park, and used the vehicle's appearance in the film as a way to advertise it when it was launched. As a result, a Mercedes-Benz ad appears before the film on original VHS copies of the film.
Major model variants have included the ML320, ML350, ML430, ML500, ML550 and ML55, along with the 4-cylinder ML230 and the turbodiesel ML270 CDI and ML400 CDI in Europe. The ML55, or ML55 AMG, featured a V8 engine made by AMG, modified body-work, and other performance features. The ML350 replaced the ML320 as the base model in the United States in 2004, although the ML320 CDI is sold in states where emissions regulations allow.
The M-Class was Motor Trend magazine's Truck of the Year for 1998. The ML320 was voted the 1998 North American Truck of the Year at the North American International Auto Show in Detroit, in January 1998.