I ordered a CF back window (plain, no duct work) and it arrived today in the UPS drop off. The panel itself looks simply awesome. Its weight is minimal so it should remove a good amount of weight (glass is heavy). My only concern is that it is very thin and may increase the sound levels in an already loud passenger cabin. Heat transfer from the engine might also be an issue...
a little heat shielding on the engine side would fix those issues.
IMHO, the best aspect of this mod is that it eliminates one of the dumbest car vestigial limbs ever known. Let's face it, a back window in an Exige S is about as useful as teets on a...(well you know the rest if you're from Texas.)
Hoping to get it installed this weekend. If so I'll post up pictures.