Tom is correct. If you want to get the best deals then your best option is to fax a couple dozen different dealerships with details about the vehicle you want, the price you're offering to pay, let them know you have a readout (from any source like Consumer Report, whoever) and are aware of dealer cost, and also let them know you're requesting quotes from other dealers. Watch the fur start flying. Sure, you'll have a few dealers who won't answer back, most will answer but stand fairly firm, but you'll end up with half a dozen dealers or so who'll haggle lower on the price to compete with the other dealers.
One other tip. Start the faxing process with at the beginning of the last week of the month. Dealers will sometimes offer prices significantly below their cost in order to get the vehicle off the lot and not incur penalties from corporate. My brother-in-law did that with the Nissan Armada he bought and purchased it $1,000 below dealer cost, and the only sacrifice he had to make was on the color and had to take what the dealer had on the lot. It's not a perfect process, and you're screwed if the vehicle you want is a popular model selling well, but the deals are out there.