For what was essentially a limited production car, the K70 did undergo numerous changes. Most of them were intended to increase the parts commonality with other Volkswagen products (which was initially nearly none at all). The original square-edged bumpers were replaced with the rounded ones of the Audi 100 in August 1971. The shifter linkage was simplified in the spring of 1972, which improved the shift action; a new synchronization design introduced in August 1972 (for the 1973 model year) further improved it. At this time the car was also modified beneath the front bumper, with new openings in the sheet metal to provide better cooling for the differential. At the same time, the L versions' rectangular headlights were replaced with twin round units which distanced the car slightly from its NSU origins. In August 1974 the three-spoke steering wheel was replaced with a padded, four-spoke item also used in the Beetle. The May 1973 introduction of an 1807 cc version with a claimed addressed performance concerns and was accompanied by redesigned engine and transmission mountings intended to reduce interior noise. The final K70s did out-accelerate the final 412s, and had a higher maximum speed with the 411/412 offering a fuel mileage advantage.