Kendall, the guy in charge of the garage drove it around with me in it so I could say 'that's the noise'. The mechanic couldn't see anything wrong, and it's expensive enough so they don't want to just replace it for the hell of it. They said maybe if I drove it a bit more the problem would become more evident so I went around a traffic circle, then came back and did donuts in the garage parking lot trying to get it to make the noise. The circle did it, the donuts didn't. It's coming from the front driver's side wheel, and it does it (once the wheels get warmed up) on the straightaway. Swerving a bit makes it stop. The mechanic's fairly sure it's a bearing, and I agree. I just couldn't drive fast or long enough in the crappy weather (along with the idiots who seem to feel it's safer to keep stomping on their brakes on icy roads) to get the wheel innards warmed up.

No clicking, no grinding, no vibration. Just a sort of circular-sounding whine, much like the sound a wheel bearing makes when it's going tits-up.

Off to call Tom...