I’m feeling a bit nostalgic, thinking back to the days when our “tour program” was just me driving a minibus with eight other travelers, and at particularly scenic spots — to enjoy the views to the absolute max — we’d take turns riding on the rooftop. (I’m back in Europe now, and I drove some of these same roads today. The views are beautiful as ever…but I stayed inside the car.)   We’ve come a long way since those early days — and these days, more than 30,000 free-spirited travelers co...