True MB DNA? Wow, I never asked me the question...It's more about feelings for me.
MB DNA is much more subtle than a list of characteristics...
You have something I always liked, it is the way the side pillars are slightly higher than the roof, so you have the windshield connected to the roof, and you clearly see the pillars going a bit higher than the roof, don't know you see what I mean. It gives a very clear shape to the roof.
The car appears more edgy, and longer. I love that detail.
You also have the rising windowline, with the strong, rising character line.
The typical bonnet, with big lines coming from the grill to the exterior of the bonnet.
A specific rear window inclination (on sedans)
Very short front overhang, and significantly longer rear overhang
Triangular rear lights (on sedans), but not always, since the W124 and 202
Very often, the chrome strip over the plate. Sometimes short, sometimes long, sometimes all the rear of the car.
Big door opener (now everybody has them, but once there were usually plates one on the competition cars)
A particular connexion between the C-pillar and the rear side, giving the impression that the windowline continues on the rear of the car (hard to explain but pretty obvious on the cars)...
Maybe I'll think to other features...
But also, an overall quite rigid, edgy shape, except on Schrempp-era.