I just installed my crossbars and measured the inner and outer lengths. Inside crossbar distance is ~28.75 inches and outer distance is ~34 inches. Each crossbar is ~2.5 inches wide.If someone has factory crossbars installed, could you measure the dimension, front to back? Or if you don't have crossbars, could you measure the outter-most plugged holes for the crossbars? That should be close enough. With my Santa Fe, I had to pry the cargo box clamps around the bars because they were so far apart. My cargo box's clamps max reach is 38.5".
I have a Thule Force XT XL and this distance should fit my cargo box.