drive times tokyo to kamikochi

firstly, thankyou for such a fantasitc website it is so helpful!
M y2 questions are, how long does it take to drive from tokyo to kamikochi? We havent organised accommodation in tokyo yet, where is the easiest place to pick our rental car up from to then drive to Kamikochi?
Secondly, as we have a car we dont have to stay near the bus routes, are there any villages out of the way places( maybe with onsen) that would be great to see and stay at around kamikocki , takayama area, we are already planning to saty one night at shirakawa go. Thanking you in advance

M y2 questions are, how long does it take to drive from tokyo to kamikochi?

Kamikochi is closed to private cars. The last section has to be done by bus or taxi as explained here:
http://www.japan-guide.com/e/e6040.html

Driving time from Tokyo to the parking lot at the entrance to Kamikochi is about 3.5 hours:
http://goo.gl/maps/qwK7l

We havent organised accommodation in tokyo yet, where is the easiest place to pick our rental car up from to then drive to Kamikochi?

I think it is more easily accessed by public transportation. If you want to take a car, I recommend to select an outlet as close as possible to your Tokyo hotel. But be warned that driving in Tokyo is rather stressful. The expressway system is very complicated.

So, alternatively, you could consider renting the car in Matsumoto.

The Takayama/Kamikochi area is generally served very well by public transportation.

Drive time will be a bit around 3 hours and a half; try to avoid peak times...
Best station would be Shinjuku, since you can get the Chuo Expressway pretty fast from there.
Takao for Mt.Takao and Matsumoto would be the most touristy places along the way