We did the entire thing, from Santa Monica Pier where the sign says it starts and right to the end, in Chicago. Our trip was mid July to mid August 2010.
Then we travelled to Niagara Falls Canada side and down to watkins Glen race track to watch Nascar, on to New York and the surrounds. Sounds like you want to do exactly what we did
. Oh, we spent time in San Fran first too. Alcatraz was cool!
Was the trip of a lifetime. We got to see so much in such a little time. Its a great topic of conversation over beers/BBQ and we are heading back next year again. Love it!
Not to do the drive though. Its one thing that is great to do, but once only. I thoroughly recommend it.
The time we went was perfect too. Vegas was excellent weather (always a highlight) and Chicago was a massive surprise, we loved it, great city (given the season we were there) so we stayed on 2 extra days there.
We also loved Niagara Falls and New York, stayed 1 street from Times Square. If you do the holiday properly, it doesnt have to cost an arm and a leg, going with 4 people makes it much cheaper too.
I better stop now, once I get on this topic I go on forever