Once you’ve got your bars and towers sorted, the biggest factor in selecting the best cargo box is its size and its shape. You want space ample enough to handle whatever you’re going to toss inside, of course. But those looking to haul a quiver of skis for the entire family or a few surfboards will want a box long enough to accommodate your hard goods, while others who just want some extra space for a variety of items can consider wider, shorter models. Those with hatch-backs that open vertically should also be sure that the cargo box won’t interfere with the door, and those who want their cargo box to look like part of their luxury vehicle should consider boxes that are made with higher-quality materials or that are low-profile, which provides a sleeker silhouette that looks better, creates less drag, and less noise than bulkier models.
Thule roof bars offer premium quality for all types of cars including those with flush rails as well normal roof rails. The Thule Wing Bar roof rails feature an aerodynamic design that is so quiet and efficient that you won’t even notice they are fitted as you drive. Thule roof bars are available in a wide range of sizes to fit small and large car roofs.
I can't comment on J carriers because I don't use them, but perhaps I should. The design weakness with Thule is the square bars, which only becomes a problem on curved roofs, but as the roof curves so must cradles cant away from each other, reducing contact between boat hull and cradle to inside edges. The cradle faces are absurdly small to start with; this rotational deviation from level makes it even smaller. Couple that with Thule's comically inadequate détente angle fixing clamp (for holding the saddle in the shape of your boat hull) and for support you are probably better off using foam blocks. So J carriers may work better on a curved roof, if I can lift that high. I've seen some people use them for composite boats so it might be OK.
I purchased a 2015 F150 and needed to upgrade my load bars for my Thule Kayak Hullavator system. I was using 58" bars on a 2013 F150 and they were just barely long enough. After measuring the old bars (58") on the new truck, I was worried they wouldn't be wide enough for my Hullavator system so I purchased the 65" bars (as suggested by Thule). I'm glad I did as the shorter bars would have allowed the kayak lift to hit the side of my truck.
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.
Hitch Mounted – These types of the rack are connected up to the receiver hitch at the back of the vehicle. They tend to be very strong and stable, and often pack in more features than you may find on the other styles. The main benefit of these types is that they are lower and easier to load then the roof-mounted versions. They also largely keep the bike out of the vehicle airflow, helping minimize the impact on your fuel consumption. The negative is they can affect your rearview when driving, they can make trunk access difficult or even impossible and you must remember you have the rack mounted when you are reversing!
Thule simply makes the best-engineered accessories (with the possible exception of the wheels that Yakima makes for kayaks). If you use square Thule bars, your kayak will not push the saddles forward (unlike Yakima, with its round bars). Thule bike trays have improved (the old ones had junky, tricky mounting hardware), and their new kayak saddles are elegant and attach with only one screw and can be removed quickly (unlike Yak's ugly, plastic saddles that are high, noisy, and have two difficult to turn thumbscrews on the bottom). Compare them and you'll see what I mean.
After reading the reviews here by some users who had issues with the older clamps, I contacted Thule support and they offered to send me a set of new metal hardware at no charge. The support rep. said that most of the problems with older design were probably caused by non-use of bow and stern tie downs, and strongly recommended doing this, even with the updated mounting plates. A few weeks later I received the plates, installed them, and everything seems to be solid but I think I'll still be using tie downs just to be on the safe side. Just noticed Yakima is now making racks similar to the Hull A Ports and also recommend securing the bow and stern. Guess they're playing "C-Y-A", too.