What brand and type of roof bars do you have fitted?
The oval aluminium type are supposed to be better than the steel square ones regarding preventing whistling noise.
Thought this had bee asked before, might be of help.
------------- XVI yes?
As well is two words!
How does a sage know everything about everything? or does he? or does he just think he does?
Remember, if you buy something you bought it, not brought it.
The whistling is caused by the air passing over the roof bars. Wrapping a bungee around the roof bar may help as it breaks up the air flow reducing the whistling.