2003 Infiniti G35 squealing

Sometimes when I back up my car and turn out of my parking spot at work there is a loud squaling noise. It occurs when I start the car after it has been sitting all day, when I put it in reverse. It seems like it might be from the steering wheel. But not sure. It stops when I put it in drive and take off. It only seems to do it when I leave work and the car has been sitting allnight. The last few nights it was really loud and longer. But some nights it doesn't do it at all. It doesn't reoccur again until I leave it sitting all night again. Hope this helps. (I'm not positive it is front wheel drive. Just guessing)