To the best of my knowledge, ride height is measured from the centre of the wheel, to the bottom lip of the fender.
M-B normally specifies a " raked " look, i.e., the rear should be 1/2 - 1" higher than the front. That should just about make it level with a " normal " load ( 2-3 passengers ).
The front fender opening is usually much greater than the rear, to allow you to turn the front wheels to full lock, and bounce the suspension, without hitting the fender.
Back wheels don't turn.
