Tourist Information Desk
I arrived in Lisbon Saturday morning at 9a.m. I went to the Tourist Info desk and was told that another person was hiring a tour car and the driver would give a guide on the sites we visited. The car was air conditioned, we shared the costs and although quite costly we saw most of the sites within 3 hours.
The tour was a bit rushed but we had agreed this at the start as the person I shared the tour with had another flight to catch in the afternoon. Check the price of the tour, where it goes to and how long it should last.