i haven't noticed any difference in handling over time.

but you are right about the squeaking/creaking trim panels. mine creaks from the trim panel where the seat belt strap comes out. it's most noticeable on the driver's side but also occurs on the passenger side. the dealer never fixed it 100% in two attempts and i even removed the trim panel myself in an attempt to fix it. i need to work on it again when i get a chance to play with it a bit. for now the solution is make sure the radio is always on so that i don't hear the creaking.