Sorry no experience with long car trips but a tip for Innsbruck.
If you are interested in mountains, you can go up to the top of Hafelekar on the Nordkettenbahnen - first a funicular and then two cable cars :
http://www.nordkette.com/en/cable-railways.html
You can stop several times on the way up and down.
Wonderful views on a clear day and a fantastic experience ( especially for people from flat countries ).