Thule have done the hard work of figuring out how to best fit it to your car, though. You just dial in the angle between the arms, hang it on your car and tighten the straps. You can lock the ratchets, and there's a cable lock to secure the last bike in place so it's harder to steal rack and bike than is typical of boot racks. It folds tidily, but it's not light.
Anti-Sway Cages – There are a few different ways that racks can be designed to minimize sway, but an anti-sway cage is the most widely used. In particular, you’ll find these on rack designs that hold the top tube, but rear mounted designs that lock the wheels can also benefit from built-in anti-sway tech. In essence, it’s just going to help to keep the bike stable in the rack as you drive. This has the dual benefit of not allowing the bikes to affect vehicle handling (especially at highway speeds) and also stops the bikes knocking into each other.
What a nightmare...spent 4 hours the first day trying to install load bars on my Audi TT (this rack was "specialy designed" for this car...HA!). Returned to dealer several times and they could not do any better. Thule customer service is a joke. They verified the placement of the load bars and the wind deflector is getting in the way of my wipers, WTF! What really iritates me the most is that Yakima does not make a roof rack for my car and I am stuck with this. Going back to dealer one more time to get proper fit, will return and go with Yakima hitch rack if they cant help.
Aluminium bars include T-track slots which allow you to use the full length of the bars for load carrying. The WingBar not only looks good but more importantly includes a device which reduces wind noise to the minimum, as well as reducing drag. Many customers leave their Thule WingBars in place from week to week, especially if they are taller vehicles and fitting is awkward.