Whistling Noise 2003 Buick Rendezvous

I am the original owner of a 2003 Buick Rendezvous. In recent months I’ve noticed a noise that sounds like wind through a bad seal (window, door, sunroof) when I hit about 35 miles per hour. To try to isolate the sound, I’ve taped off the sunroof, doors, hatchback as it seemed it might be a bad seal. The sound continues. Any ideas as to what else this might be?