I respectfully disagree on the rear doors- look down from above at both cars and you'll see that the rear doors pick up the rear flare about midway fore-to-aft. And if you like, check the P/Ns (as I have)...500E/E500 rear doors are assuredly 124.036-specific, unlike the front doors.
One small distinction, if we're getting into details, is that the 500E front seats are set 2 or so inches farther apart, to accomodate the wider tranny tunnel. Not so the rears; they're identical to a 4-door Sportline setup.
And is the steering wheel the same as an SL500? It's 390mm in diameter, and I thought was a 500E and Sportline-only item