Update!!! We went to change the bulb last night (it was showing that it was "out"), and as soon as we removed the rear light cover, it came back on! Apparently there is some sort of short in the wire...we adjusted it a little, replaced the light cover, and it is working fine now. If it happens again, we're taking it back to the dealership as the car is still under warranty. Saving the $5 bulbs for a later day.