During the winter of 1980–1981, the final exterior for the W124 program was completed, chosen as the leading proposal by design director Bruno Sacco, and approved by the board of management in early 1981.

[10] It had one of the lowest coefficient of drag (Cd) of any vehicle of the time (0.28 for the 200/200D model for the European market with 185/65 R15 tires) due to its aerodynamic body, that included plastic molding for the undercarriage to streamline airflow beneath the car, reducing fuel consumption and wind noise.

The saloon/sedan, coupés and convertibles had optional rear headrests that would fold down remotely to improve rearward visibility when required.

This feature was not available for the T-model because of its specific layout (no space to store the retractable headrests), but the estate serially came with a "neighbour-friendly" rear door that was pulled in the shut-position silently and automatically by a sensor-controlled servomotor.

This allowed the use of a tighter fitting rear gate, minimizing the cabin noise in the T-model - sometimes an area of concern for station wagons.

[11] The estate cars (chassis designation S124) came in 5 or 7-seat models, the 7-seater having a rear-facing bench seat that folded flush luggage compartment cover and an optional (in the US until 1994) retractable cargo net.

[1] Offered with five-cylinder diesel engines built by Mercedes' Indian partner Bajaj Tempo,[12] the W124 was replaced there in December 1997.

The W124 was also offered as a long wheelbase saloon targeted for taxi companies, but the more luxury equipped version was also used as a limousine.

Mercedes entered an agreement with Porsche to assemble the vehicles at their plant in Zuffenhausen, as the automaker was in crisis, and its factory capacity was underutilized.

Following the impending release of its successor, the Mercedes-Benz W210, the remaining units of W124 were fitted with additional accessories found in stock models such as walnut wood steering wheel (optional), airbag for front passenger, walnut center console glove box, electric rear blind and rear seat side window sunshade (optional).