I hear a pop noise when rolling to a stop.
 

The noise I hear sounds like I ran over an acorn. It sounds like it's coming from the rear, but I can't be certain. When I notice it is at stop signs, rolling into my garage, or parking. I have heard the noise without pressing the brakes, so I don't think it's the brakes. I have 56K miles on it. Does this sound like wheel bearing issues?

Maybe suspension bushings?

I had a similar problem a couple of years ago, mine was definitely coming from one of the rear wheels. I thought it could be a bearing or brakes, it got louder as I was coming to a stop. While rolling (at any speed) it was like a constant grindind noise. After closer inspection (removing one of the rear wheels) I found a snail trapped betweeen the rotor and the shield! Its shell was intact, but the poor snail was cooked already! LOL.

That might be it. Because I hear it almost every time I'm pulling into my garage. There's a slight bump where my driveway enters the garage. When I'm rolling in and going over that bump, I hear the pop. When you say suspension bushings - is that the sway bar bushings?

Are the OEM Sway Bar bushings slit where I can pull them off the sway bar without removing the entire sway?

^^^ I crawled up under there and refreshed my memory on everything (I installed the rear F Sport sway bar on my previous IS350).

Should I stick with OEM bushings or go with something like an aftermarket poly-urethane? If I go with aftermarket, what size will I need?

Maybe you are running over a lot of acorns hahahah