@tye1138 - '01 996. Haven't tried engine off down a hill yet.
@vcyclenut - I don't think it's in the steering. I typically notice it as I'm creeping to a stop at a light going dead straight.
It seems relatively rhythmic to the rolling speed of the tires. My first thought was something was rolling up inside the tire then dropping. I know that is beyond highly unlikely but that's the way it felt if that makes sense. Very reminiscent of those colored plastic things you'd put on your bicycle spokes when you were a kid that slid up and down, but if you only had one.
I'm a stickler about chain lube, but we've had a ton of rain lately and my baby has had to endure it. I should probably throw it on the stand just to make sure I don't have a sticking link. I've actually had to take the clutch apart twice and pry the plates apart. Open clutch cover + rain = bad. I know, I know. I should be ashamed of myself, and I am.