I'll hijack rpowell's post and tell you my travel dates so that hopefully you can give me guidance on how to find the previous, respective, winning PRICELINE bids.
Dates of Travel: 6/27/14 - 7/6/14
Car Class: Minivan
FYI - the Costco rental price is less expensive than the lowest Price.line, Hot.wire, and Expe.dia rental of the same class, so that is what I will be using as a base price ($567).
Thanks in advance for your assistance!