Renting a car in Madrid and travel will include Portugal. Is there any restriction concerning using that rental in both countries? Thanks, Mary
You won't be restricted from driving into Portugal, but you should return the car in Spain to avoid the very hefty one-way dropoff fees (charged if you pick up the car in one country and return it in another).
Some of the smaller, local rental companies state you can't take it out of Spain. The international companies (Hertz, Avis, etc) impose no restrictions.
Thanks so much for your replies!