It is very difficult to comment on an itinerary for a country as diverse as Portugal without knowing your likes and goals. That being said, we will make suggestions based on our personal experience and knowledge of the country. As I write this, I see that you have received some fine responses, some of which are in harmony with my opinions. That's where the personal thing comes in and gives you the opportunity to choose what fits your style.

Unless you have a desire to stay on the beach, it is not necessary to stay in Cascais. I would stay at the Hotel Britania (one of our favorites) for five nights. It takes at least three days to see Lisbon properly. Take a day trip to Cascais/Estoril by train (about 40 minutes from Cais do Sodre train station at the waterfront - trains every 15 minutes). You can walk along the shore promenade from Cascais to Estoril and board the return train there if you wish. Take a day trip to Sintra from the Rossio Station next to the Praca dos Restauradores.

Now some difficult decisions. While the Alentejo is worth a visit, two days are not enough to do it properly and it is out of the way if you're heading north. I would not go to Estremoz. Obidos is a cute town, which can be enjoyed in an hour and the Pousada isn't that terrific - so my advice would be to skip staying in Obidos. Coimbra can be done in a day. The Quinta das Lagrimas is quite lovely.

The Douro and the north are the best parts of Portugal and more time should be spent there. The Pousada in Mesao Frio is gorgeous. The area around and north of Guimaraes is worth more time. Based on the above, the following is my suggestion. When you leave Lisbon (if you pick up your car at the airport, it is easy to get on the road) stop and visit Obidos and then head up the coast to Nazare, a coastal fishing village for an overnight. The next day, drive to Coimbra by way of Alcobaca and Batalha. From Coimbra, head to Pinhao on the Douro and the Vintage House hotel for two nights - wonderful place and location. You'll enjoy the scenic drives through the picturesque Douro Valley. Then over to Peso da Regua for two days and more spectacular views and day trips. You'll certainly have plenty of time to perfect your driving ability around the curvy roads. Next Guimareas, with a stop in Amarante on the way, for two nights with visits to Barcelos, Braga and Viana do Castelo. Finish with three nights in Porto (consider dropping your car at the airport to avoid driving in the city) at either the Porto Carlton on the river or the Infante de Sagres in the heart of the old town. Contrary to negatives expressed by others, we love Porto. (Be sure to visit the caves of the famous Port Wine makers across the river in Porta Nova de Guia. There's an excellent special exhibit we enjoyed at the House of Sandeman and a museum there as well.)

So what I'm suggesting would look like this:

Lisbon - 5 nights Nazare - 1 night Coimbra - 1 night Pinhao - 2 nights Peso da Regua - 2 nights Guimaraes - 2 nights Porto - 3 nights

This gives you an efficient driving schedule and maximizes your time for your first visit. The longest drive will be from Coimbra to Pinhao. I think our travelogues will fill in many of the details for you. Have a safe trip.

Regards, Don Toronto