Priceline is sketchy for cars sometimes (in my experience). I remember a couple of years ago, I bid for weeks at all sorts of prices for a one-day rental in Ft Lauderdale and NEVER got anything.

A few months ago, I bid for 5 days in Kauai and did great.

I've struck on two different summers trying to get a mini van at LAX.

Now I've been bidding (albeit low) for Kona for a 10 day rental and can't seem to undercut the National rental I have already reserved (that included an advertised special and entertainment book coupon together).