The other thing about San Francisco is that they have recently removed all the remaining FREE street parking, and the only way we can go around SF is to park in expensive $6 per hour garages, near our destination.
I would recommend a convertible from LA to SF and Napa driving on Highway 1 up the coast.
If you want a slightly cheaper and less pretentious view of Wine Country, go through Sonoma Valley, just West of Napa. There are some great spas and accommodation in the vineyards around Sebastapol and Santa Rosa in Russian River