The Mercedes-Benz W163 M-Class SUV was introduced in 1997 for the 1998 model year. It is a midsized body-on-frame suv with seating for 5 or 7 with an optional third-row seat. 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.