^ahh you are talking about the infamous Disco butt syndrome..
Well the W220 ( previous S class) has fans in the seats and so does the new S class..
And they have massage aswell, but as you said its an extra cost option..
Im pretty sure that this new E will get those seats aswell.. but ofcourse at a price..
And as you said your kingdom for a cool vibrating butt.. so i guess it shouldnt be a problem
