Have lived in the Bay area now for about 20 years and in that time have done several roadtrips and hosted quite a few UK friends/relatives who have covered the bits we've missed and the good news is that there is something for every taste - the harder trick is narrowing it down and not trying to pack so much in that you end up behind the wheel the entire time! However some things that might make that narrowing easier are a couple of practical issues.
1) Pacific coast drive is wonderful but a big mudslide has closed the section from Carmel to Cambria since 2017, expected opening is summer 2018
https://www.mercurynews.com/2017/09/08/big-surs-southern-access-to-stay-closed-for-one-year/
2) I haven't been up to the wine country since the fires so don't have firsthand experience but they were pretty extensive
http://projects.sfchronicle.com/2017/interactive-map-wine-country-fires/. In good times imo the area is almost as pretty as Stellenbosch but no idea now. On the plus side places will be keen to attract tourists so you might get some good deals in what is often an expensive area, I prefer Sonoma to Napa. If you are into wineries but would rather skip until fully recovered then those depicted in the movie Sideways round Santa Ynez are not quite as scenic to visit but a lot cheaper/laid back than Napa and will likely be on your route anyway.
If you like hiking I'd say visiting Yosemite is a must, all of our guests have been gobsmacked by its beauty. The waterfalls will be spectacular at that time of year and large parts of the park should be accessible although a bad late storm might mean you need chains.
https://www.nps.gov/yose/planyourvisit/spring.htm. Rather than stay in the valley or do the drive in from say Groveland we prefer to stay in one of the lodges/condos in Yosemite West which are great if you are part of group although can't remember what access is like at that time of year
http://www.yosemitewest.com/maps.html. There are several entrances to the park, to vary the scenery I'd plan on going in one and out another
https://www.myyosemitepark.com/park/which-yosemite-entrance. The two other parks Sequoia and Kings Canyon are also beautiful and a bit quieter but they may have limited services in April.
Weather wise you might get a couple of late season storms but April is heading into dry season and in SF in particular it is probably sunnier than than the summer given the fog then. Not great beach weather, at least until you get further south, but you should be able to find some great wildflower displays if you like hiking. Peak bloom very dependent on timing of our rain but here was 2017s display forecast
http://www.visitcalifornia.com/attraction/californias-spring-2017-wildflower-forecast.
Unless you fancy visiting Death Valley I'd leave Las Vegas to a separate trip - it makes an excellent start/end point for a loop tour visiting Utah's wonderful natural parks even if you don't particularly like the city itself like me. I'd also skip San Jose, there are lots more interesting places to see.
Hubby hates theme parks and I'm not a fan of Hollywood so a lot of LA attractions pass us by but I love its gardens, Huntington in particular
https://www.timeout.com/los-angeles...nical-gardens-and-hidden-oases-in-los-angeles and I am keen to visit the Getty center. Lots of great places to see round San Diego and Joshua tree park is beautiful but you do add in at least 6 hours of driving to/from even before you see anything given your flight out of LA.
tl/dr - Spend a few days in SF getting over jetlag seeing city with a day trip to either western wine country to avoid worst of fire damage or to Marin country/Point Reyes. Drive down Hwy 1 via Santa Cruz to Monterrey and Carmel. Spend a few days in area shopping in Carmel and visiting Monterey Bay aquarium including popping down to Big Sur. Head over to Yosemite via Arch rock entrance and spend a couple of days hiking. Leave via Fish camp and head back to coast to see Hearst Castle and explore some of Santa Barbara sights/wineries. Then either a couple of days in San Diego or LA itself.
pm me if need anything more!
