Whistling noise while car in motion

The filter could do it strange as that sounds

If it's under the hood,

I'm going with a dirty throttle body plate. Clean both sides of the throttle plate w/ throttle body cleaner

If it's external, like a wind noise,

look for plastic aerodynamics being pulled loose, scraped up and now "ragged" on the edges. Even luggage racks make noises (especially if the adjusters are loose)

Sometimes it's quick and and fast find a wind problem (like a mirror or trim or other) BY CHANGING IT'S SHAPE, even slightly. Achieve this by slapping a few inches of that "Green or Blue Painters masking off tape over the suspect area, then see if it goes away or changes at all.

Return with good news,

The Medic

Tie up the radiator fan so it can't spin in the wind. If the noise is gone, replace the fan motor. The clue is the noise will stop before the car comes to a complete stop. Also, it never occurs when increasing the engine's speed when the car is standing still.

Dandy. I worked for a very nice family-owned Chrysler dealership, and they had the same policy. Chrysler would cover almost anything after the warranty expired, even years later, as long as it was documented while it was still in warranty. That is an example of "customer-friendly" business practices. There are some larger manufacturers that are well-known to have very customer-unfriendly business practices. They put quick, short-term profits ahead of customer satisfaction and loyalty. I'm happy Honda isn't one of them.

Happy to hear this is solved.