Well it's interesting since it is how you said nothing is installed if the installed screen is empty and the rest are available but not installed. You could try presenting it with that USB with the maps on it but then I dont reckon its set up to do anything. What I achieved last week by accident but corrected now in mib2.

Is this the official Seat Turkey line that connected services are not available. What about VW since the two companies are the same or Skoda. Perhaps those are populated over the air if you had connected services.
Hi Tell;
I did as you said but nothing happened.. :(
 
It must be that Seat doesn't support connected services in Turkey. May be a license issue.

You could enquire what the other VAG brands due. Connected services are so connected to the car I can't believe that a retrofitter would offer you something a dealer can't at some future point although if offline maps can be performed then that's one. Far too early I reckon for retrofitters and hobbyists to have cracked that.

Why one is interested in whether Seat will allow the cars to receive offline map updates if they don't have an annual subscription. Since you haven't got anything that's academic at the minute.