Hello from Sweden

I'm new here and I begin with asking a question!
When my Mustang (2003 V6) reaches around 100 km/h I hear a swishing sound from the windows. Both the windows on either side of the car and also a swishing sound from the front window somewhere, hard to tell exactly where it comes from. Anyway this is very annoying when driving far distances

So is this normal for a Mustang? Can I do anything about it?
If I get any faster like 130-150km/h that swishing sound turns into a tornado in the car and I have to raise the volume on my music to hear anything
I mean that sound gotta come from somewhere..
Thanks!