actually, and i only know this from tinting so many in the 80's, there is a slight difference at the front of the door where the frame meets the main dor section right above the mirror where the very front of the glass comes to a point
On the later (J-B) there is a small section of guide or rail that covers the very point over the glass.
Thats usually the quickest way to tell if they're HQ doors or not as a lot of people removed those top corner guides
i would say the wedge was put there as a guide to help the window locate properly as they're not supported as well in the HQ because of the lack of extra support from the extended guide

Maybe someone can put pics?