Curious about one thing: what's the total weight you're planning to haul up there? Safety is HUGE for me, so check your manual for the dynamic roof load limit first. Honestly, even with a solid Thule Motion XT XXL Cargo Carrier, you gotta make sure those Yakima RailLine Towers are torqued EXACTLY to spec so nothing shifts at 70mph. Safety first, lol!

For your situation, ngl, the Thule WingBar Edge for Cadillac XT6 is the way to go. I've tried many setups over the years, and it's WAY quieter than the Cadillac XT6 OEM Roof Rack Cross Rails. Plus, if you're mounting a big box like the Yakima SkyBox 16 Carbonite, the Thule bars offer a much more secure fit on those flush rails, you know? Definitely worth the extra cash for the peace of mind... gl!

Facts.

So, basically, when you're looking at flush rails like on the XT6, you gotta realize that the mounting points are super specific. I've been doing the family road trip thing for years now, and I've tried many different setups on my SUVs. The thing is, the distance between those rails determines how stable ur cargo box is gonna be. If they're too close, the box wobbles, which is LITERALLY the worst sound when you're doing 80 on the highway.

In my experience, I actually started with the cheaper bars I found online because I wanted to save some cash, but man, the whistling was insane. It sounded like a flute was stuck to my roof. I eventually bit the bullet and got the more aerodynamic ones from one of the big brands you mentioned. Honestly, it was night and day. My current setup sits really low to the roofline, which is huge for keeping the noise down and helping with gas mileage—cuz lets be real, these big Caddies already drink plenty of fuel lol.

I found that the 'aero' style bars are the only way to go if you want to actually talk to ur kids without yelling over wind noise. I spent about $500 for the whole kit including the feet and the bars, and over the years, it's totally paid for itself in peace of mind. For a large box, you definitely want the bars that overhang a bit so you have more room to grab onto when you're mounting it. Just my two cents, but go for the premium brands over the factory ones if ur worried about the noise level!! Good luck with the trip.

Just catching up on this thread. Like someone mentioned, the noise and MPG stuff is definitely worth thinking about, but I kinda disagree with the idea that you have to drop a fortune on the big brands right away. You might want to be careful about the installation process tho, especially with flush rails. If youre doing it yourself in the driveway, some of those mounting kits are a real pain to get lined up right. Have you considered a hitch-mounted rack instead of the roof? It might be way easier if you aren't tall enough to reach the roof easily. Also, are you planning to leave the bars on the XT6 all the time, or just for this trip? I would suggest checking your total clearance before you commit... honestly, I almost took out my garage door once because I forgot how tall the box made the car. Better to measure twice now than deal with a huge repair bill later, ngl.

Honestly, before you drop $600+ on big brands, you gotta consider the aerodynamic drag. I'm a stickler for specs, and those bulky setups can tank your MPG by 10-15% on the highway. I'd suggest looking at some lower-profile aero bars from Rhino-Rack. They're basically just as quiet as the high-end stuff but way easier on the wallet. Just make sure the T-track is compatible with whatever box you get!! Good luck.