The W105 was nicknamed Ponton, along with its Mercedes model siblings, from its introduction, because it employed ponton, or pontoon styling, a defining post-war car design innovation that unified a car's previously articulated bonnet, wings, body and running boards into a singular, slab-sided envelope.

The Mercedes 219 (internally W105), had a 2.2 L inline 6-cylinder engine, and uniquely featured a bodyshell that combined the stretched nose of the more luxury W128 and W180 models 220a and 220 S(E), but shared the regular standard wheelbase cabine, with shorter rear doors, with the 1953 entry-level 4-cylinder Mercedes W120/W121 models 180 and 190, to offer an intermediate no-frills 6-cylinder model option.

In the following year, Mercedes-Benz introduced the 6-cylinder 220a which was visually similar to the 180, but with a 170 mm (7 in) longer wheelbase, and an entirely new rear suspension design.

The 219 from the a-pillar forward was identical to the long-nosed 220a, including the single-carburettor 2.2 L 6-cylinder engine.

Inside, the 219 used the simpler instrumentation of the small car, along with bakelite trim instead of woodgrain.