Need a code to unlock audi concert

[ngedolim]

hey guys,

I have an audi TT 2003.
how can i get my pin code to activate my audi concert?

serial is:
AUZ2Z3B1786050

THANK YOU!

[ngedolim]

I guess this info might be needed as well:
its a grundig and there is another serial (not sure what is it): 4B0 035 186 G