Back to the folding bike idea, and I'd look at Bromptons for a quick, small fold and good comfort on the road. Bike Fridays have the comfort (and then some), but with the exception of the Tikit they don't fold that fast. Having said that, I've taken my Bike Friday (Pocket Rocket) on packed gravel with no problems. Two of them fitted quite nicely into the trunk of our rental car in BC last year, but it was a pretty big rental car. (The Friday does have a quick fold, but it creates a bike that's sort of clunky, while the Brommie folds much smaller).

How far do you plan to ride? What sort of roads/trails?