When I think of Costco, I think of bulk packs of toilet paper and giant boxes of cereal. However, they are actually a giant referral source for new car sales (700,000/year)--and now they are adding used vehicles to the mix.
They plan to have their certified-vehicle program rolled out to all stores by the end of 1st quarter in 2010. They have tested the concept in Denver, Phoenix and San Diego. The price point for used vehicles is based on the lowest price advertised online by the dealer at the time the customer is looking for a vehicle--then Costco customers are offered a price below the lowest posted price. This is usually within $500 of the dealer's invoice.
I'd love to hear from any dealers who participate in this program--and what your experience has been like.