When I went a couple years ago, we flew to L.A., spent a night there, and then left on Saturday late-morning to get to Indio (it was only a 2-day festival then). The drive took well over 4.5 hours because of very heavy traffic in most big city areas of Calif. Traffic into the general area wasn't all that bad. We ended up missing a few bands that we wanted to see. So give yourself a lot of extra time if you're driving there.
Oh, and if you're thinking of camping, the lot is a giant, wide-open space with no shade and lots of dust. When the sun comes up, you'll roast in your tent. The "rules" are strict about no alcohol, etc., and they did check our stuff pretty thoroughly, but you can still sneak in some booze if you're crafty and want to have a nip.
