Those are one of the most important part of the window/regulator assembly. Without them in place there is 100% chance you'll shatter the door glass....trust me....been there and done that years ago !
They MUST go between the horizontal track and the glass at the rear mount shown in the above picture.
On the front of the horizontal track you'll have a phillips head machine thread bolt that screws into a plastic retainer mounted in the glass itself. At the rear of the horizontal track you'll have a 7/16 head bolt that goes through the track, through that raised flat washer, the rubber hose, the glass and threads into the retainer rear track guide plate shown in the above photo.
Installing E Body side glass is one of my favorite things to do