Today on our 2013 Acura RDX, we'll be test fitting the Thule Sonic XXL rooftop cargo box, part number TH636S. We'll begin our test fit by placing the cargo box onto the vehicle's crossbars. After positioning the clamps over the crossbars, we'll unlock the box and unlock the lid, exposing the two closest knobs. We'll turn the knobs to bring the clamps up around tightly against the load bars. … see more >