I know what your talking about. I notice it every time I back out of my parking spot. Usually is "clicks" as your refering to as I start to turn the wheel right while I'm backing out. I haven't checked to see if the noise is related to turning the steering wheel or a mechinism relate to going from park to reverse. It does it consistantly every time from the time I got it that I just asume it is okay.
It is defenately not the door locks. Imagine the noise of the wheel on "wheel of fortune" the click noise it makes is very similar to the noise I hear but imaging it clicking only once.
Is that the noise you are hearing when in reverse after being in park when you back up?
I imagine I'll look at it one of these days and figure it out but I really wouldn't worry about it.
If I stop hearing it I am going to think it broke....