We did the West coast for our honeymoon 3 years ago:
London to LA for 2 nights (Universal studio was main visit for us)
LA to Santa Barbara for 2 nights
Santa Barbara to Carmel/Monterrey for 3 nights
Carmel to San Fran for 3 nights
San Fran to Yosemite for 3 nights
then flight back to London.
We drove up the coast road for the entire trip which was marvellous, and San Fran is a fabulous city to end up in.
Yosemite was the real highlight of the trip - I urge you to consider that as there's so much to see there and the facilities were first rate. We were going to include a trip to Death Valley and down into Vegas, but we ran out of budget for that unfortunately.
If we were to do it again we'd consider staying for slightly longer in each location and definitely longer in Yosemite.
Oh, and LA Airport is the most god-awful place on earth - not a great way to start the holiday after such a long flight. Landing late in the evening it took forever to get a shuttle bus to the hire car place..then driving on the wrong side, at night, tired in an unfamiliar city was pretty tough.
San Fran airport was the complete opposite though - it's by far the nicest and most civilised airport I've visited. Even the hire-car drop-off was in a multi-story car park attached to the airport so no shuttle buses required. A relaxing way to end the trip.