Some general comments
Insist on a copy of the VMI (Vehicle Master Inquiry) and PDI (predelivery inspection) on a new car.
It may be too late to get a free paint pin ( little bottle of touch up paint) and a free, really nice key chain, from the dealer's parts boutique. You can do it at the moment of delivery, it's not too late.
Make sure the salesman at the time of delivery, gives you a thorough demo of the car's features, they are paid for that anyway.
Take a good look at the body and interior, lok for scratches and damage. if you find any have it fixed by them.
If you like the dealer, ask them for 10-15% off parts and service prices. Since you bought it there they will probably agree.
Buy right away, the Mercedes Benz set of rubber black all weather floor mats, (The ones to protect the carpets and floor mats in your new car.) You will nevermore have to worry about stepping accidentally in wet paint, dog crap, or chewing gum and then trying to remove it, these are hazards in Francisco and the bay area, you would be dismayed if you stepped in that stuff.. works in snow and slush and rain too.
Shouldn't run you over $75-$90 for the set when the discount is applied by the dealer.
No reason to go for window tint if you live in Alamo. If you spend your summers in Palm Springs or Albuquerque then that is another matter.
If you only want tint for the "mystique" look, common in LA or the bay area then go ahead, well, then that is another matter.
Smoked tail light lenses for the first time, (the 2013 model year), are now dealer-available accessories for the w212 e class. I hate them because I see no aesthetic value to them and think they allow LESS visibility when you hit the brakes.... but that is a matter of personal preference.
It is also a good time to review the extended warranty coverage, if you want it. I personally bought all I could get, (the cars are super complex now, dealer labor rates in some Nor Cal MB dealers are $175 p/h and maybe more, and climbing,) on 8/25/12, so I am covered to 8/2017 and 135k though a lot of the later waranty coverage on it is not totally bumper to bumper.
Bargained it down to $1,945, which some people don't realize thas azsdde3d warranty coverage is VERY profit laden and can be haggled with, and folded the coat into the car loan.
But i then paid off everything in full last week, I hate being partners with banks in anything, and hate paying interest to them.