No bug shield. I do have tow mirrors. They don't have chrome covers.
I did some testing this evening. Rolled all the windows down and that didn't change anything. But I decided to run it up to 15-20mph in reverse, and the whistle still happened in reverse...*groan* So now I'm thinking that it's very likely not wind noise?
I feel like my noise may have a loose connection with engine speed/rpm, but it's hard to detect. I drove down a long hill, put it in neutral, and I feel like the noise got slightly quieter as the rpms went down while I was coasting.
I thought that maybe when I got home I'd spray some belt dressing on the belts, so I did that...but no change.
I feel like I can possibly hear the/a whistle/squeal ever so slightly when idling, but when I rev the engine in Park in my driveway it still won't get any louder.