I know you said the fuses are fine. Did you check in both fuse panels, the one on the dash and the one in the engine compartment?
Also, have you checked the bulbs? Tailight bulbs are easy to get to, just raise the liftgate and you will see 2 phillips head screws on each side for each taillight. Remove the screws and pull housing straight out away from the body. There are 2 locating pins on the back of each housing towards the outer edge that secure the housing to the body. These pins fit into rubber grommets and sometimes they can be tight getting on or off. Once the housing is off the bulbs can be accessed from the back side.