E-buggy tour is the best way to see the sights of Lisbon.
Sit back and relax as you zoom through the city streets, with your mates. You will be guided by a monitor who'll lead you through the tour that starts in central Lisbon 'Praça do Comercio', and end up at Lisbon's Beer Museum - which is perfect if you want to kill two birds with one stone and have a cold one after your tour through Lisbon.
Note: You will need to give deposit like car rental, and to show your driving license. Each group will have a to choose a designated driver, so make sure its one who's sober.