What are the three bits of tape on the window regulator for in a 1970 Bug?

Alrighty then ... The three bits of tape originally held some felt like material that is meant to sit in between the window regulator and other parts of the inside of the window like the bar from the quarter window. It does this in order to create a buffer between the regulator and the other bits so as not to obstruct the path of the regulator. When the path is obstructed the regulator wont operate properly. Moral ... replace all worn exterior weather stripping !