If you have a bare roof, then you'll probably need horizontal rails that clamp in above the doors. They don't look very good and they could very well do damage to the roof of the car.
Once you have rails then you'll need a rack or clamps to attach to it. I have the Yakima fat cats. Got 'em for like $150. You could theoretically do the whole project for less than $500, but again, the issue with damaging the roof of the car should be fully investigated.
Your best bet is probably to take your question to a message board for owners of your car. Got the best info on my rack from the Subaru Outback and Subaru Impreza message boards.
62" 2008 Burton Royale
Burton Cartel bindings
Salomon Synapse boots
Last edited by The Jake; 11-27-2011 at 12:15 PM.