Why not exchange info? There's nothing in the purchase agreement which makes the details confidential, and there's nothing wrong with consumers sharing information to their mutual benefit. Consumers Reports publishes this sort of info every month. Remember that a dealer is under no obligation to sell you a car at the price you want just because they sold it to someone else at that price.

I got $6k off on a $102k sticker for my MY07 C2S Cab in August 07. I had negotiated the discount based on a MY06, but it came in as an 07 and the dealer honored the price. Local dealer - about 20 minutes from home, one of a several within a reasonable drive.