Car Rental - Algarve Region

A little more info would be helpful. Where in the Algarve will you be, how long do you need the vehicle, will you return it to the same rental location or a different one? How many passengers?

Auto Europe is almost always the best option. They would offer pick up and drop off in a number of locations. And, after using them for years, I've never had a bad experience.

Thank you!

Pick up in Lagos, drop off Madrid, rent for 7 days.
2 people.

My advice would be to not drop of a car in Madrid which you picked up in Lagos, as the drop fees could be as much as 300 euros. If you want to drive to Madrid, I would recommend taking a bus from Lagos (or Faro, or a few other possibilities in the Algarve), to Seville, and pick up your car there (or train to Madrid). The bus ride is 4 to 4.25 hours using the Spanish bus line Alsa, or an hour more on the Portuguese Eva, but with more options on your starting point. Note that the prices quoted by Auto Europe do not usually include the fee to drop-off in another country- it is on the list of exclusions, and price depends on the company and countries involved.

Well, driving from Lagos along southern coast of Portgual into southern Spain and then Madrid so will check options.
There didn't seem to be any good train routes from southern Portugal to Spain (Marbella)?

No car company is going to offer inexpensive rates for dropping off in another country. And, no, there is no train from Portugal to Spain from the Algarve. It's surprisingly difficult to get from Portugal to Spain by public transport. Some people find it quicker to fly from Faro to Madrid.

You don't want a car in Madrid. So, your best option would be two rentals - one in each country

Well, if you're really set on driving along the coast, Tavira is a pretty little town near the eastern border or Portugal. Eva runs a couple of busses a day from there to Huelva, Spain, about 50 miles away. I haven't been to Huelva, but it's a big enough city to have multiple car rental outlets, so you might consider starting your Spanish drive there.