[Nyororin]

Unless you are very good with mountain roads covered with ice and snow - Do NOT make the Nagoya - Takayama trip by car. I`ve done it, in autumn, and even then the roads were icy in the mountains. Even if you ARE familiar with Japanese roads, small mountain roads, and ice... I wouldn`t suggest it because others driving often are not so you`ll end up inching along as they drive below 20km/h. Really, I think the idea of driving around Japan to be a great one, but January is NOT the time to do it. Even if you stay out of the mountains, last night the entire Nagoya expressway was closed down due to snow and ice. It`s far far worse in the mountains - yes, the roads do close often.

The expressway should be open in all but the worst, however - as others have pointed out - the expressway in Japan is anything but free. The cost of renting a car alone may be cheap, but adding in gas and expressway costs... Plus the sheer amount of time it takes to drive places when you`re not familiar with the roads... Would you really be saving?

ETA; I also highly advise against going with a kei - (called K-car above). I cannot even begin to count the number of little keis that seem to slip and slide off the road or get stuck in snow. Kei vans slip and flip on roads a normal car would have no trouble with. If you`ll be ONLY in a big city, putting around, a kei is fine. Any real driving...? Umm, you couldn`t PAY me enough to drive one.