Annoying humming sound pretty much at all speeds, but more so on the highway Edit
Probably more often than not, this will be one of your wheel bearings. Bearings go bad in Hyundai's more often than Ford's break down. And that's a lot!! Bearings are covered under the bumper to bumper portion of our Warranty, so if you're under 60,000 miles bring it to your nearest dealer and get it taken care of.
Rear view mirror vibrating a LOT Edit
Parts of the interior seem to be chipping and cracking Edit
Depending on your mileage, this may be covered under your warranty. Take it to your nearest dealership if you (a) have less than 60,000 miles or (B) live near a "good" dealership and can give you a deal. It can happen.
Problems with the amplifier Edit
The sunroof/moon roof of the 2003 (and possibly later) models has a drain tube that runs to the left, rear wheel well. This tube runs over the top of the amplifier and if it becomes clogged/falls loose/dry rots, water drained will fall onto the amp and cause it to short. Extremely annoying, but covered under the bumper-to-bumper warranty.