Is the Panamera's design flaw being improved?

Is it just me or is the Panamera's rear quarter glass divider becoming less visible? Clearly the photos have different light conditions and photoshopping is easy, then there is the tinted glass option and the top one has an accentuating chrome framed glasshouse, but still...

Since the Panamera's launch I have wondered about the odd rear door design. Why didn't Porsche's designers and engineers add a real third window behind the door instead of the awkward door shape?

The drawing from 2005, in a Spiegel Online article announcing the Panamera, suggests a lower roof line and a third window as part of the C-pillar. Or maybe a fake greenhouse glass extension which is called either a quarter light filler (pane) or a cheater panel as I found out. (BTW Another subtle but important difference seems to be the front wing, which appears more pronounced then the production version...)












Is it true that the former CEO Wiedeking demanded a design change to sit comfortably in the back as a relatively tall person? Has the door design and overall glasshouse been influenced by that?

BTW 1
My bet is that the Panamera's facelift will feature:

1. more curvy front wings (fenders)
2. slightly accentuated rear wings
3. Re-designed front and rear bumpers which will look more muscular and leaner

Overall more stance, yet visually lighter. Unfortunately, as a friend recently pointed out to me, doors aren't usually part of a car design facelifts...Any thoughts?

BTW 2
There seem to be a number of design schools an engineering philosophies about the greenhouse of cars: B-pillar design, the use of quarter glasses either as part of the doors or as integrated feature of the C-pillar. Food for some posts...