After our visit to Porto we would like to rent a car in order to travel to Douro River Valley for a few days. We are trying to find out whether there is a car rental company that is located in an area where driving won't be a hassle trying to get out of Porto. Another wrinkle is that we will be picking up the car on a Sunday. Appreciate hearing from others who have rented a car in or around Porto before heading to Douro.
Thanks in advance.