Just checking in. Seems my "vibration issue" was just me unfamiliar with the new road I was taking home. I've driven it every day since then and haven't noticed anything. I'll also note that I checked my tire pressure a couple of days ago and found that my tires were overinflated. Most were just over 40 PSI, and one was at least 45 PSI. I've lowered them all to about 37 PSI and they perform much better in the snow/slush.