Originally Posted by
malmostoso
Good point, however from Andorra one could easily drive into France (say, to Perpignan) and return the car, then take a train to Barcelona.
Seems like that would work.
The OP doesn't really say anything about timing. With plenty of time, trains might generally work, with car rentals/taxis as needed for certain side trips. But if this is a quick spin through 5 places, I like the idea of renting a car for the first 4 stops and then taking a train to BCN to avoid the hefty drop off fee. In any case, the OP shouldn't need (or want?) a car in Paris or Barcelona, just in-between.