The 124 chassis may have debuted in 1986, bur work on it started years earlier. It was to include a great deal of automotive innovations at the time, including retractable rear headrests for visibility, an oxygen sensor in the exhaust pipe which helped control air/fuel mixture, a molded plastic baffle pan under the engine compartment, and 4Matic - Mercedes-Benz's proprietary all wheel drive system. The 300E was an early offering built on the 124 chassis. It was a mid-size, rear-wheel or all-wheel drive vehicle with a fuel-injected inline 6-cylinder engine. Power output was steady at between 158-185hp depending on the year of production and options. The Mercedes-Benz 300E parts that made up the frame and suspension were also some of the first to components to be mass-produced from high-strength, light-weight steel. All of these factors together made one of the longest lasting vehicles on the road today.