Pre-Purchase Inspection
I would ask the dealer to get the vehicle report from a Mercedes dealer that may have some maintenance records or whatever. You can also ask a Mercedes dealer yourself, but really getting the records from Mercedes should be no issue if this is a dealership and not some one man operation.
The most "honest" inspection is usually free and provided whenever you get your car serviced. Dealerships have their techs comb through the car for repairs (not always necessary) so that the SA can sell you the work. But a pre-purchase inspection should highlight major issues and you could possibly sue the dealer if they didn't discover something major that surfaces.
I'd check the car fax
Check the engine serial number to make sure it's after the head bolt change
Throw $50 to a local mechanic to give it a once over
Check the warranty
Work out a price
Screw the dealers! They all suck


