It is possible to get around some of Calif on buses or the train. But, I would not recommend it. Especially for two or more.

The added convenience is well worth paying a little more to rent a car. If it would even cost more to rent--rental is pretty cheap here if you avoid the add-on "insurance" scams at the counter. Or, try Priceline.

How many are you and where and when do you want to go?