I can give you one specific example: Wartburg (East German Automobile manufacturer) exported cars to the US, UK, and other countries in Europe and South America (where Wartburgs were also built under licence) in the 50s, 60s, and 70s. I don't have any figures for Wartburg imports to the US but just under 20K Wartburgs were imported to the UK between 1964 and 1976.

Enough Wartburgs were imported into the US that at least one dealership in California received hate mail from people who didn't agree with Iron Curtain cars in the USA.