2007 Mercedes Benz keys locked in the trunk ..help

I worked on Mercedes any years but none newer than the late 90's models but I can tell you it can be done by removing the back seat. You will most likely run into a gas tank that is in the way but might be able to see them and fish them out with a coat hanger or something. The tank is removable but for the trouble it is I would call a locksmith.

Unfortunately i have the same car and did that before and there are so many anti theft devices that even a locksmith couldn't get in. Usually you cannot push the unlock button or handle from inside if the car knows it is locked. It wont open. I had to call the dealer and give the vin number to get a valet key made just to get into the trunk. I assume you cannot get in the cockpit either obviously. Sometimes depending on the car they can remotely unlock it but i have the exact car and they couldn't do mine. My onstar or whatever the sos is called is not active so maybe if yours is they can.