FYI: The actual office location (and drop off) is on the south west corner of the park.
Dropped off the car here without issues, maybe because I'm Gold, or maybe because I did a very careful check for even smallest nicks and had them marked when picking up the car in Ljubljana (after reading the other reviews here). One star off for office being closed at 3:30pm - had to call the number on the door and the guy came few minutes later. Luckily, I had a working SIM card.