I have a couple proposals.
You're right, HHGttG is a no-go. Too complicated.
Also, I'd like to stay in LA on our way back and then fly home on my own a few days later. This would free up some space in the RV for the long haul back to Seattle for you guys and whatever swag you get at Coachella; it would keep me from going insane from being cooped up with a bunch of people for so long (I like you guys, but I'm sort of nutty about being around people for too long, I'm going to be strung out from the crowds, and I don't want to be a downer), and let me spend some time with my friend down there. Since I'm not one of the RV drivers, it wouldn't affect the drive schedule.
I can get a greyhound from Indio to LA for $23, so we wouldn't have to battle LA traffic.
Indio to LA on the Greyhound is a go for me. Thanks!