FEEDBACK:
Guys, I did not get a chance to reply or thanks the members who have provided the valuable in-put on this thread. I have been able to complete my trip via Sadan vehicles Honda City and Corolla.
Honestly, I was expecting the road to be little challenging but surprised to see that even honda reborn, toyata prius which have low ground clearance easily crossing the babusar top. Actually only maximum 3km to 4 km of the track is not metaled and part which is not metaled is actually in last stages for final tar to be laid down on it. So this part was also in a very good condition for car crossing.
Actually, road which was little bad for vehicles was the part between Chilas till RAIKOT bridge, here there were many patches which not metaled, lots of landslides, rocks all over the road, I did my entire trip from Islamabad till hunza in 12 hours considering my lowest speed between chilas till RAIKOT bridge of 30-40 km/hr.