The K70 retained NSU's naming convention, as introduced with the Ro 80 — with K denoting the German word Kolben (piston) and 70 designating an engine output of 70 PS (51 kW; 69 hp).

The clutch and gear box were directly behind the differential, and the three comprised a compact package which necessitated a relatively high bonnet but which also maximised the proportion of the car's weight carried by the front wheels, and the space available for passengers and their luggage, characteristics that the K70 shared with the NSU Ro80.

At the same time, the L versions' rectangular headlights were replaced with twin round units which distanced the car slightly from its NSU origins.

The May 1973 introduction of an 1,807 cc (110.3 cu in) version with a claimed 100 PS (74 kW; 99 hp) addressed performance concerns and was accompanied by redesigned engine and transmission mountings intended to reduce interior noise.

Tall by contemporary standards, the K70 benefited from the space saving characteristics of its front wheel drive layout and compact engine installation.

[2] The relatively large glass area also led to the car carrying an above average proportion of its weight above waist height, however, rendering a wide track particularly important in order to ensure lateral stability.

[2] As publicity for the Mercedes-Benz S Class would stress when that car was launched in 1972, this was the least vulnerable position in terms of the risk of the fuel tank being punctured in the event of a crash.

The steering column was angled in order to reduce the risk of its being pushed too far back into the passenger cabin, and while seat belts were an optional extra, at least on the domestic market, mounting points for them were standard.

For the Volkswagen dealership network, their staff trained over many years to promote and service rear-engined air-cooled cars, the appearance at relatively short notice of the water-cooled front-engined K70 presented a challenge.

[9] The K70 together with the VW 411/412 ended up being the only cars ever to be produced at Salzgitter, the plant being turned over for engine and transmission manufacture for the entire Volkswagen Group,[10] which continues to the present day.