The Moskvitch 400-420 was a car from Soviet manufacturer Moskvitch introduced in 1947. People in Rüsselsheim remember dismanteling the Kadett production tooling after World War II, to go into a large number of freight cars on their way to Moscow. Before the war, the Russians had independently made 500 units of the KIM 10-50 as a loose copy of the four-door Opel Kadett, the production of which was consequently cancelled. As most of the Opel tooling was for the two-door model, the Russians converted this into a somewhat crude 4-door configuration with large external hinges. Although Opel was US-property, GM did not recover control of the factory until 1948 and were therefore unable to contest the transfer.

A factory called MZMA (Moskovsky Zavod Malolitrazhnykh Avtomobiley, that is, Moscow Compact Car Factory) started to manufacture the modified Kadett as Moskvitch 400-420 in December 1946. "400" meant a type of engine, and "420" - a sedan body. In 1954 it was replaced with externally identical 401-420 model, with engine uprated from 23 to 26 hp. Also a cabriolet 400-420A and wooden van 400-422 / 401-422 were made.

Some of the production was exported, among other countries to East Germany and Norway. Production ended in 1956, when the design was heavily outdated. Private users in Norway at the time needed a license to buy a new imported car. This did not apply to Russian cars that as a "friendly gesture" were supplied in exchange for fish. In all, 247,439 Moskvitches 400/401 were made, after 107,608 Kadetts in Rüsselsheim 1937-1940.