My husband and I are taking European delivery of a car in Munich and will end in Nice, France. We’ll be traveling for 2 weeks and need advise on the itinerary; where to go, how long in each place. The trip is this July.
You should look at the map of the driving route and see what cities are close to it and decide which ones you want to go to
https://goo.gl/maps/gXgXQSDYsC42
Nice your end point is good for 3 days I think and Munich your starting point is ok for a couple of a days.
How long in any place all depends on your interests.