I like your idea about the '61 Caddy, SixtyEight... a '61 Caddy or '61 Lincoln convertible would be a great road trip car, I think... (I don't really care for the '59 Caddy styling, but the '61...).
I try and always rent convertibles when I'm in California...Mustangs or Thunderbirds several times in recent years. For road trips closer to home, I'm in my Grand Cherokee, M3 or my girfriend's 330Ci with the top down.
I've never really spent anytime in the Northwest...I want to explore up there eventually, and I want to drive to Alaska and drive up to Prudhoe Bay. I need to take time in the next year to visit friends in Portland and Seattle.
The south really has no big appeal to me (I lived in the Florida Keys as a kid), but I would like to explore the Appalachia of my ancestors--SE Kentucky, SW Virginia, NE Tennessee-- eventually...
I miss the rolling hills (esp. this time of year) of my native Eastern Ohio, and the nearby hills in SW Pennsylvania....there are some absolutely incredible driver's roads there (miles and miles of deserted, twisty two-lanes over rolling hills, green valleys, etc). Though I wouldn't really want to live there again...not much opportunity in my line of work (though Pittsburgh is a neat city, IMHO).. the Midwest in general doesn't hold much attraction to me (haven't lived there since '97), but I do enjoy visiting old friends in Chicago, Ann Arbor, Cleveland and Columbus (all places I lived in my 20s).
I've seen bits and pieces of the NE before, but I'd like to see more, esp. upstate NY and New Hampshire and Vermont.
There are enough interesting places in Cali that I can go there every year on vacation for years to come..
I want to drive more in Europe--I've never been on the Autobahn in Germany, but I've driven on Italian Autostradas... I want to explore the roads in the Alps, France, and Scotland eventually... some of the most exciting roads I've driven were along the Meditteranean coast of Italy (even in a diesel Merc A-class or diesel Vectra!) and the roads north of Milan in the hills around the lakes...