AMCs made in Germany? Yes, they were, albeit only few of them. Karmann in Osnabrück, a manufacturer producing for many renowned makes, was chosen by American Motors to make the American way of drive popular in Europe and especially in Germany.
Karmann was and is a no. 1 address well-known for excellent build quality. Famous cars like the VW Karmann Ghia, the VW Beetle Convertible, the Rabbit Convertible, and the BMW 6-series coupé were made there.
Javelin parts were delivered from the U.S. and assembled in Rheine. Production started in January, 1969, and ended in July, 1970, after only 281 Javelin SST had been produced. Most of them had automatic transmission, only 13 cars were delivered with a 3-speed manual transmission.
Not many Karmann Javelins have survived. Most known examples are in need of restoration, the presumably best one is located at the Karmann museum. Should such a car drive across your way, get it! You can hardly get a rarer vehicle.
If you want to take a look at a Karmann Javelin data sheet, you can do it right here.