When I drive 40 mph and moonroof open, I get very load resonance. Has anyone else had something similar?

This happens with all wind instruments. To change the sound, you need to do one of the following. 1) Change the size of the opening 2) Change the speed of the wind passing over the opening 3) Open a valve.

This has happened on all of my cars/suv's with sunroofs. Try what works best for you. I usually close the sunroof a little. You can open a window also. Some have used wind deflectors with success.

My HiHy has the Toyota wind deflector, which cuts out the drumming. On my other cars, I would just crack open the rear windows.

Nice "wind instrument" analogy.

My Volvo's sunroof is pre-set from the factory to open about 90% of the way when you open it. Supposedly, that dramatically decreases the resonance as opposed to when it's open 100% of the way. So definitely try different sized openings.

Most of the time, if I open the sunroof, the weather is nice enough that I'm opening all the windows all the way. I get no resonance at any speed in the Highlander under these conditions.

We're talking about putting one on. How do you like it? Have you had any roof top hauling issues?

It really deflects the wind, I can have it open while on the freeway and its really quiet. The downside is that I think its a bit too good, I would like a little more wind in my hair.

I have a Thule Evolution roof box that I haven't had time to mount...but it looks like it should have enough room even with the deflector installed.

Thanks for the info. I think we're going to get one, though the added benefit of lots of wind coming in will be somewhat diminished. It should be worth it if the humming is lessened.

I have a Highlander also I I just barely crack my back windows with my sunroof open.