These fairings are easy to mount and neither will actually "not fit" on your car. Yakima is super-rigorous with their testing, so go with what their Fit Guide recommends. If you're buying it from a store, tell them that you saw that the Yakima website gave a different size and ask them why they're recommending the smaller size. They can double-check with Yakima to ensure a proper fit. I installed Yakima racks for 10 years at a large shop.