Mexican Hilux noise?

Hello, I'm new here so forgive me if this has already been asked. When the rear windows are down in my 2017 dual cab Hilux I hear a noise coming that sounds like it's coming from the rear tires at 60 - 80 kilometers per hour. It is a loud Woo woo woo whoo that to me sounds like ut of balance tires. I took a service tech with me and he said it is turbulence at that speed. He even tried to get me to ride in another Hilux just to show me that they all do it. But the rear tires are showing wear on the leading edge outside treads at just 6,000 kilometers. They blamed this on the traction but I have owned four other Toyotas and this has never happened on any other truck. Is anyone familiar with this noise?

 

Could it be the tires are overinflated or you need an alignment? I’d try that first before anything else.