Hi there! I totally get the wind noise worry—it's the worst on long trips. For your CX-9, I've tried both and here's my take:

1. Mazda CX-9 OEM Roof Rack Cross Bars: These are super affordable and fit the car's look perfectly. However, they're a bit noisy at high speeds.
2. Thule WingBar Edge: Honestly, these are so much quieter! They're pricier, but the aerodynamic shape really stops that annoying whistle.

I'm really happy with the Thule set for my heavy cargo box. Good luck! 🚗

Curious about one thing: what's the actual weight of the cargo box you're planning to use? I'm asking because budget is a huge factor for me, and the price jump between brands is wild.

From what I've seen, here's how the value stacks up:

* Yakima JetStream Bar Aerodynamic Crossbars: These are a bit cheaper than Thule but way quieter than OEM. Great middle-ground for the price.
* BrightLines Mazda CX-9 Roof Rack Crossbars: Honestly, these are the budget kings. They're super affordable, though maybe not as "premium" feeling.

OEM is okay, but if you're worried about noise, these aero bars are usually worth the extra bucks. Anyway, let me know the weight and I can give better advice!

Seconding the recommendation above regarding the Yakima stuff! Honestly, I've tried many setups over the years, and safety is my top priority when hauling a heavy box.

In my experience, you should look at these two:

1. Rhino-Rack Vortex ROC25 Flush Roof Rack: Super secure and usually cheaper than Thule. It's solid as a rock at highway speeds.
2. Inno Rack Aero Base System: A great budget-friendly alternative that's surprisingly quiet.

Personally, the Rhino-Rack is the best choice for reliability without breaking the bank. Hope this helps!

Can confirm this works