That Hertz transfer website is intriguing -- given that I know of no other practical way to rent in one European country and return to another -- but I suspect it would be difficult to use in practice. At least for Americans, who have to arrange their air transport to the continent in advance. Like if I flew into Spain and out of Germany, I'd have to get lucky to find a car in my arrival city that needed to be repatriated. Still, I'll remember this trick just in case I ever need it!