Just remember that you're only going to see part of CA. A significant part of the state is north of SF and there is even some away from the coast to the east.

Regarding driving the coast from SF to SD - good luck. I suspect you'll get tired of it before you get there and head for the closest freeway (yes, they're called freeways in CA).

All that said, it should be a nice week. I suggest doing it in the spring or the fall.