I just bought a 2012 Ford Focus (obviously) SE Hatchback - 57,000 - and I'm not much of a mechanic so I'm hoping to see if anybody on here can help me figure this out. At 71-76 mph there's a loud hum coming from the rear (wheels, cab..not sure) Strange part is that at 74 mph it's the loudest. I was able to get it to 74 this morning on a turn and the hum started to pulse. I brought it in to the dealership, they weren't able to find anything wrong and they just rotated the tires...same result. After some online searches my guess is that it's the wheel bearing or an alignment issue. I'm going to try and bring it in to the dealership again and have them re-diagnose as I have ~2,000 left on the warranty. Anybody? Anything?