Efter the war, Opel production facilities frae Rüsselsheim (caurs) an Brandenburg an der Havel (trucks) wur cratit up an transportit tae the Soviet Union as pairt o a lairger reparations package agreed upon bi the victorious pouers. Frae 1948 the prewar Kadett wis manufactured as the Moskvitch 400/420: it continued tae be produced on the edge o Moscow as a Moskvitch till 1956.
GM imported the Opel Kadett B, built at the recently closed plant in Bochum, Germany, into North America starting in 1966. American and Canadian car buyers weren't especially enthusiastic about these cheap little cars, but sufficient quantities were sold that they were fairly easy to find in American wrecking yards through the 1980s. Here's a '67 in a Denver-area self-service yard that managed to outlive most of its contemporaries.
It had some crazy mechanical issues. At one point it stumbled and stalled because the carburetor had come loose from the intake manifold and I had to tighten it back down! Another time, my brother was driving it and the brakes failed. Somehow the end of the brake shoe that meets the brake cylinder piston had become worn on one side, causing the piston to slip off the end of the shoe when the brakes were applied, losing braking and squirting fluid all over.