Right. It's the rear gap that I think is the most challenging. I drew these up quickly.
I had a few ideas to cover the front gap, but nothing solid about the rear gap.
The challenge are the gaps.
The pictures you show have a similar concept to mine, except that the pillar guides are on the door, where I have them as an extension of the windshield. I didn't go that route as I didn't like the look of it on the door, it seemed a static extension of the windshield was better as it was stationary. Now when you open the door, I fear it's going to be "flimsy" where having it on the door would be better.
Which is why I thought, if you were to have something on the door, why not a vent instead. This is more aesthetically pleasing, to me, and fills the front gap.
Here's the pillar extension.
Here's the vent - which is attached to the door.
The rear gap remains to remain a challenge. One challenge at a time I guess. I was thinking that maybe some wizard trickery with the glass, where it maybe is shaped in such a way that when completely up, it overhangs past the rear just enough to fill the area snug, ... Maybe the combination of glass shape and guide rails, ...