You're thinking of ITAR (International Traffic in Arms Regulations), though I don't believe there was any actual "team up," which is why the G-MAG is reverse-engineered, vice made in Germany to original Magpul specifications (i.e. under license).

I have not really found that there is a substantial AR market in Germany, so much as great enthusiasm on the part of the few who do aspire to own these arms. The change in German law that resulted in such things as the semi-automatic StG-44 has opened the window somewhat, but ther average German still has a long way to go to get an AR added to his Waffenbesitzkarte. Few hunters have an active interest in military-style arms, and most sport-shooters are still doing well to graduate beyond .22s.

AC