Extendable crossbar for a vehicle

A roof rack system for affixing to a vehicle having a plurality of mounting locations system is provided. The roof rack system comprises a crossbar assembly comprising: an axis of motion, e.g., translational motion; an internal structure; a first section; a second section; a third section; a first end mount; and a second end mount. The first and second sections are configured to translate, in opposite directions, along the axis of motion relative to the internal structure. The internal structure is configured to cause the third section to be centered between the first and second sections as the first and second sections translate. The first and second end mounts are coupled to respective outboard portions of the first and second sections. The first and second end mounts are configured to mount to respective first and second mounting locations, e.g., mounting locations of the vehicle.