Whistle noise when over 70 mph

Hi all. Did aircon service before going for a long trip in europe. The first day i started driving there over 70 mph i could hear this anoying whistle noise .thought it may be the windscreen seal but that looks ok. Feels like is coming from centre of dash but not so sure as is hard to tell. Had car for 4 years now and never happend b4.

The car is bmw e91.318 diesel.58reg.

Any one can help. Thanks