My wife and I are planning a road trip starting in Seattle, visiting most of the national parks within reach, and coming back to Seattle via the Pacific coast. We plan coming in August 2010. We have holidayed and driven in USA several times, but not through the mountain regions. As I guess we won't be back this way again, I'd like to make the most of it; plenty of Kodak moments wanted!
I will post the planned itinery below but I'd be grateful for advice as to whether we are packing in too much and won't get enough out of the trip because we skimp on locations. I have got estimated drive times from multimap but I guess I will have to add to them as we are likely to be held up by RV's etc.
Plan is:
Day1 arrive in Seattle
Days 2-5 Seattle and surroundings
Day 6 Seattle to Spokane visiting MT Glacier NP, 4.5 hrs driving
Day 7 Spokane to Kalispell 4.5 hrs driving
Day 8 Kalispell to Great Falls visiting Glacier NP 4hrs driving
Day 9 Great Falls to Yellowstone 4 hrs driving
Day10,11 Yellowstone
Day 12 Yellowstone to Jackson Hole visiting Grand Teton NP 3hrs driving
Day 13 Jackson Hole to Idaho Falls with time along the Snake River valley
Day 14 Idaho Falls to Boise with detour into Snake river Sceneic Highway and bird of prey Canyon
Day 15 Boise to Bend 6 hrs driving
Day 16 Bend to Florence and the Pacific coast 3.5 hrs driving
Day 17 Florence to mid way to Seattle on the coast road, (any suggestions?)
Day 18 Seattle

We do have the capacity to stay an extra 3 days or so. Suggestions as to how this could be best spent, more time in the various parks perhaps? Also would a four wheel drive vehicle be needed? We haven't checked on hotels yet but I guess we will need to book Seattle and Yellowstone in advance. Any suggestions for nice places to stay?

Any suggestions gratefully received.

Harry Mac