My car has a major case of the whistles, as stated above it's most noticeable around 50-60 range but can be heard 80+ too. Mine's an auto-stick and mostly noticeable when the top is up and the mentioned speeds. I can hear it too with the top down at higher speeds but it's more of a sharp whistle, not as annoying as the other when the top is up and the radio is down so you can either think or have a conversation with someone.
The dealer said they'd look at it but would need the car for several or more days and I just couldn't bear to part with her that long...or think of some mechanic "cruising" around in it for "research" for that long.