L.A.
Priceline! Start you bidding low. I was able to get a midsized car recently for $10/day. I would start at $5 day and see if it is accepted. If not, go up a buck or two.
They do add the taxes on (I dont think there were any extra Priceline fees) so add a little more for that. I dont believe the taxes would be any extra than doing any other company though.