They're supposed to retract. They don't "fully" retract in the sense you no longer see them, but they're supposed to retract nearly all of the way. When I had my 92 Cutlass many years back, the sunroof didn't move properly. I believe the drive gear was stripped, and I ended up just pulling an entire sunroof unit from a car in the junkyard and replacing it.
I also had the sunroof in my 2000 Regal break, to where it wouldn't retract properly, and would only tilt. I never looked into fixing it...but it acted similar to a power window with a broken track.