...or is the rollbar a pop up, like in some BMW Convertibles?
The glass rear window is a good thing.

 

It will be the same system as in the 1- and 3-series 'verts.
By the way, the current model also has a glass rear window . . . just wanted to clarify that.

 

Eager, my comment about the glass window was based on BMW experience with the dreaded plastic wondow. I hated that thing.

 

^ I agree - not horrible when brand new, but after a short while, when they start scuffing and scratching, they are like having a wall back there.

(My previous post was just meant to clarify so that people wouldn't think the glass was a change from the R52 to the R57)