I buy a lot of tickets 0-7 days in advance. Sometimes there are no longer advance purchase restrictions - I flew to LAX last week for less than a normal ticket costs me at 14 days out (and it was over spring break for much of the West Coast)
But as others say, sometimes a package is a good way to go. Out of curiousity I checked Expedia and a flight with car was almost equal to what I paid for airfare only (but since I wasn't paying for the ticket and the package was not with my preferred vendors, I went with the airfare only option)