Today on our 2013 Kia Optima, we'll be test fitting the Thule Sonic Medium rooftop cargo box, measuring 13 cubic feet in glossy black, part number th634b. With the tule rapid reverse roof rack system assembled on our vehicle, we'll begin our test fit by placing the Sonic directly onto our load bars. With the feet hanging out of the bottom of the box, we can adjust them as necessary to fit around… see more >