Well I went into one dealership with a cost list of what they pay and what they charge me MSRP. I did not work at all. They earn $3100can off the top before any options. They earn money from the options too. I asked for them to sell me some options at their cost and they dropped the cost of the car $100 (wow, not). So it depends, do they need your buisness bad enough, in most cases no. The only time I hear of dealers giving deals at mercedes is if they need to move more product out the door. Why would they give us a deal on something thier sure to sell in a few weeks anyway.
Good luck, it's worth a try.
Good luck, it's worth a try.