You can take your car all the way to Shogran. The Shogran road is much steeper than Murree or Nathia gali. It is almost a continuous incline. Use low gears while climbing and upon descending, DO NOT use brakes too much. Just put it in low gear.
If you want to spend the night on the way, Balakot or Abbottabad is best. But there's really no point in staying in Balakot, since Shogran is less than two hours away. Better stay at Abbottabad, the hotels are much better, you can eat out at different places and it also has some nice places to shop. Next morning drive to Shogran.
There are no sightseeing places along the way, but if you have the time, you can drive to Thandiani from Abbottabad (I always do that when I am in Abbottabad). It's about 28 kilometers and the drive is beautiful. Thandiani is also a nice quiet picnic spot and its the highest point in that area so it has some good views. There is also a beautiful forest rest house at Thandiani. If you have contacts in the Forest department, you might be able to book it. It's a great place to stay.
