Parker - A fairly fast route leaving from Lake Como would be A-9 to A-50 to E-35. However, if you'd like some great scenery, once you get near Florence get on SR 222 route, just a little south of Florence. It's called the Chianti Road, and it's a very scenic drive once you get a little more south of Florence. You'll go through Greve and Castellina, great Chianti towns and a place to get lunch or a snack. As you continue south you'll come into Siena on SR2 route.