If you like to drive, I would also recommend renting a car. I drove the LAX-SAN route twice this last summer (going and coming back). There's not a lot to see during the drive, which is OK as it's probably better to keep your attention on the road. A group of kids must've not been doing this as they almost rear-ended me. As it was they left a 20-yd. long strip of rubber on the road when they hit their brakes and fishtailed to a stop in a cloud of burning rubber a few yards behind me. Anyway, try to miss the rush hour traffic, and you should be OK. Even better if you can use the carpool lanes (give someone a ride?).