There was a post on this some time ago, I did a search and could not find it:

I am in the process of trying to find out where the "e body whistle" is coming from:

I taped every exposed moulding edge on the windshield. Still whistles.

I taped over the hood and fender gaps. Still whistles.

I taped over the leading edge of the doors. Still whistles.

The car is covered in green masking tape and the whistle is present and annoying as ever.

I have experienced this in both a 'Cuda and a Challenger, so I think it is safe to say that the noise is not coming from the grill shape or header panel. Could it be coming from the rad support? How about underneath the car?

Has anyone else had this, and, if so, what did you do to fix it?

My sig car whistles at 30 to 35 mph with the top up or down. Sounds like it's coming from the drivers side. I'm pretty sure it's a 'factory installed option'!

Still open to suggestions.....

Is it coming from the front widows? I got inside my doors and adjusted the glass so it sealed against the weather stripping better, it helped a bunch.

There are these clear plastic/celophane-like sheets that are supposed to block the wind that install between the inside of the door and the door panel. They are often gone/rotted so I never knew they were supposed to be there, you can find them on e-bag...

Could it be a hairline crack in the heater box? The ventilation system air buffets around in there and any crack will cause a whistle.

Jim

I have owned two challengers one was a hard top and the current one is a convertable and both whistle. There have been many discussions on this board throughout the years and no one has found the source of the whistle. Good luck finding it. If I was you I would work on something else as I doubt that you will find it.

No other car has a cowl like the E body... try tapin up those plactic grilles and see what happens

Challenger1, lakerism, jfmoparts, ucudant and ironwolf, thanks for the suggestions. I will try everything and then some.

Is it the side mirrors? Common to both...My Breeze side mirror supports look like airfoils.

It really does sound like it is coming from the mirror, but as you speed up the sound moves to the center of the windshield.

Also, putting your hand out the window and blocking airflow to the mirror has no effect.

I have the same problem and have never figured it out. How about air coming up inside the steering column? Is that possible?

These can help you find those pesky hard to find noises that only occur during overt the road conditions

http://www.etoolcart.com/wirelesschassisears-wirelessjsp97202.aspx

http://www.etoolcart.com/wirelesschassisears-wirelessjsp97202.aspx

Did you try taping up the gap between the hood and windshield (covering the wipers and bridging the gap with tape? Or maybe the gap between the fenders and hood? or maybe the door handle, both bodies use the same basic handles.
jt

Challenger, same view: