Well there was no 2015 E550 so that just makes it the 2010-2014. All E550's had real leather, it was an option on the E350 and most had MB-Tex which is a vinyl like leather, but not real leather. I believe airmatic was standard on the first couple of years and then an option in later years. Airmatic tends to be expensive when it goes, more of a maintenance item so the more miles a car has, the more likely the airmatic will go. Navigation, bluetooth and backup camera I think were pretty much standard. Navigation was part of the P1 package and probably 95% or more of those cars had those packages, you might find one or two oddballs where the dealer ordered a stripper model. The real nice options would be the pano roof, bixenons or dynamic led headlights, keyless go, dynamic seats, rear entertainment system, heads up display, driver assistance package (distronic, lane keeping, blind spot), power trunk closer, parktronic, etc.