Here's a update: I dropped the car off at the shop before dropping my wife off for work so I could use her car. Being that it was in the 20s, the noise was even more pronounced. The guy behind the desk parked it in the back and he heard it. However, later on in the day when the mechanics had time to finally look at it, they couldn't make the rear make the noise. At least one of the guys heard exactly what I've been trying to explain, so they know I'm not full of crap...lol. I'm beginning to think a ball joint (upper contro arm?) might be going bad. I'll find out more today.