I had the rear seat base off yesterday and was amused to see, stamped into a piece of sheet metal next to the seat belt clasps, Made in Germany. So not only component sharing but metal  pressings too.

You will  be surprised how many parts for all VAG (and not only) - are assembled in different countries. I work in a company that supplies all factories (BMW, Daimler, Ford, GM, VAG, PSA - and others) - with parts for the assembly lines. Almost 80% of the parts are produced outside of Czech.

there is case when czechs produce better parts for VW Passats

and import worse model of same part for Škoda Superb