In TNP they probably have their own rules, I last summer came from Styria to the parking lot around 1 a.m. and planned just to nap a bit until 3:30 when I planned to go on the trail, but a TNP warden came and started hassling me that I can't sleep in the car, so after negotiating and explaining that I'm from far away and have to start almost in the middle of the night to reach the starting point on time, I rather moved the car a couple km lower along the road, thinking he won't bother me there, but the guy on the way back when returning to Mojstrana slapped me with a fine for improper parking (100€), although two days later when I returned I saw countless cars parked along the road with no fines..., and I didn't obstruct anyone and parked there only overnight, in the morning I went to the parking anyway and paid the fee. They just make up rules as they like...