I'm not so sure about dealers selling at a loss but there certainly was a lot of press last year about the Mercedes vs. BMW sales competion going into year end. Whether BMW was offering additional incentives to the dealers to make sales during that last week, I don't know.
One such article:
2008 X5 4.8i Space Gray/Tobacco, Premium, Sport (includes AD), Active Steering, HUD, Tech, Comfort, Cold, Climate Package, 3rd Row, Prem Audio, running boards, OEM hitch
2005 X5 4.8is Imola Red, Nav, Nappa, Comfort seats, OEM hitch
2004 X5 4.4i Sport (sold)
2004 X3 3.0i 6MT (sold)
2002 M5 (sold)