Mounting procedure for window regulator and rear side window and such a unit

The method involves assembling a window regulator (22) and a glass (20) with each other, before assembling the regulator or the glass on a rear quarter panel (1). A reception cut is realized in the rear quarter panel to equip the glass with the window regulator. The window regulator equipped with the glass is introduced and immobilized into the reception cut provided in the panel. An independent claim is also included for a rear quarter panel set for a motor vehicle.