rear window:........:replacement w/ a 2003 model

my uncle has a 2001 S and for the 2001 it has a plastic rear window and sooner or later that thing gets all foggy and messed up and u cant really see and makes the car look really F'd up...well on the 2003 model it has a glass now which look way better then the 2001 model.... do u think it will be possible to replace the rear window of a 2001 model with a glass version from a 2003 model with out replacing the whole roof??