i took my civic up there with 6 people on board and it climbed like a champ , however this was 3 years ago, when road was okish.
i came back last month and the road is pretty much in a bad condition right now, and taking the car will be torture for it.
its better to hire a jeep from kiwai, u will be charged only 1000 rupees extra, from shogran ull still be hiring a jeep anyway to visit siri paye.