For the last couple of weeks now when I shift into reverse on cold mornings, I can hear a "screeching" sound or "squealing" sound ... kind of hard to explain. It doesn't make this sound after a couple of shifts back to park and then reverse again. Could this be a result of low trans fluid????

 

Slipping fan belt or alternator belt?

 

Slipping fan belt or alternator belt? If it a clunking, grinding or a chirping, it could be the gears of your transmission.

 

It might be more than low trans fluid, but one problem is the 5R55 trans doesn't even have a dip stick, so it is difficult to check. I'd take it in to the dealer and let them look at it, but before you do, I'd open the hood and have someone try to pinpoint the noise.