Power Window stopped working ! I have not had the car long so did not know if they slowed down ! I took my door apart and found that the regulator tape had been greased in the factory . So the grease in the track was hard and sticky . Once i cleaned out the track , installed a new regulator tape and sprayed the track with a marine dry lub , the window works fine . My window stopped when the motor drive wheel chewed up the regulator tape . So i was lucky to not have to replace the motor . So then i took all the doors apart , cleaned the regulator tape and track then sprayed with the dry lub . If you have the same regulator tape , you need to do this before you burn out the motor or the drive wheel chews up the regulator tape. Rubber door stops helped to keep window up while doing this project . The nylon locking clip , i was not able to get the locking clip out of the guide block without breaking it , so nice to have some , before you need them .