Wifes Accord 2012 Coupe 4 cylinder on the highway maybe 55+ MPH there's a whistling sound exactly where it's coming from is hard to detect. Sounds like maybe the from grill or windshield area. There's nothing I see obvious that could be causing it, anyone experienced this??

 

Several things can cause whistling...

Do you have anything sticking out of the car? My car had an antenna on the rear window that whistled. The fix was to put heatshrink on the coil part of the antenna.

Check the rubber foam around the doors.

Possible serpentine belt squealing?

 

Definitely not a belt noise it's a very distinct wind/whistling just not sure from where. Don't see any gaskets ripped or anything like that. It can be such a tiny thing it'll probably never be detected.