I found a 3 day Xbox Live Gold Code in one of my CDs.
On this is the following:
2013 Microsoft Micorosoft Corporation - One Microsoft Way - Redmond, WA 980 … United States
Is this now usable in Germany? (On the website, you could only use codes in those countries where you bought them, but I do not know if this "law" was in effect before 2013 and now applies to all cards in the past.)
Just enter and test
I do not think that works because of the country code.