No, really, these things are seriously quiet while driving. They aren't inaudible but probably the closest you're gonna get without flat out removing them. I can't imagine any other cross bars being this quiet. And they give you rubber stripping to cover any holes (well, troughs actually) that might otherwise upset the laminar flow and cause unnecessary noise. Very nicely done.
Secondly air pressure will try to push the boats apart from the bow. The Js are attached to the crossbar in a clamp fashion tightened with two thumb bolts. These can slide on the crossbar. The edge of your factory rail will stop them in the front, but then the rear racks will tend to slide together (toward the center of the car), making a bigger air dam. I cut and taped a strip of wood to the crossbar between the opposing rear Js so they could not slide. (I saw another car with Js and the rear racks had come together making huge air resistance and although not separated one of the kayaks had lifted from being seated in the cradle....yikes I would not want to be behind that guy!) Check all tie downs every time you stop or if you here or feel anything unusual.
To save you time, The Rack Warehouse lists the most popular selling Thule 480R Rapid Traverse Foot Complete Car Roof Rack fits alphabetically by Auto Manufacturer. You'll find perfect fitting roof racks for most of today's top selling vehicles on this list. Thule 480R Rapid Traverse Foot Complete Car Roof Racks are designed for vehicles with smooth of naked rooflines (no racks or attachments). If you don't see your vehicle on this list, simply click on the Thule Fit Guide at the top of the page, enter your vehicle information and the Thule Fit Guide will do the rest.
With a Thule roof rack, you’re all set to head off on your adventures and make sure you have everything you want with you. When combined with other Thule products, our roof racks are also a starting point for carrying the extra special gear that lets you live your passions – with holders for your bikes, your skis, your canoes or kayaks, and your surfboards. Not to mention extra-secure roof boxes and spacious carrier baskets for special cargos