According to this site, it can be done with a small car:
Yes, it can be done with a small car.
The rest is gravel / sand.
It's only 19 km from the city, but it took us 1h 15 m to get there, because of heavy traffic in the city and slow driving in the outskirts of Tirana. But it's worth, the views are very beautiful!
So if reached from Kruja side, is it all unpaved road?