try craigslist.org for carpools. car rentals are of course an option, as well as greyhound out of vega, la, or palm springs (or almost any socal location for that matter). Palm Springs is the closest commercial airport (30 min from the venue) , but flight prices are high. Anywhere around LA would be cheaper.
Don't mislead newcomers to the driving techniques of LA. 95 all the way? Good luck. Your time may be right, but there's traffic, my dad drives the freeways alot, and I'm thinking 2 hours from Malibu to Palm Springs, average speed, 80. Geez, don't kill yourself to get there or cause an accident that holds the rest of us up just to hear the music. Like someone said there is an airport in Palm Springs. Coachella is close to Indio, aren't there hotels there too?