I would wait...in fact I
"DID" wait.
Mine had 49,500 on it when I got the GMPP.
Warranty now goes to 104,500.
I didn't see any point in having (and paying for) overlapping warrantys.
The GM FACTORY WARRANTY will cover ANYTHING except brakes and rotors that actually WEAR OUT. At least my dealer does.
Window motors would be covered FOR SURE.
Texas Jim