Our RX350 has a bluetooth ( hands-free ) phone connection. That works great. However, when using that phone, the other person has difficulty hearing due to a "fluttering noise". This noise becomes very loud as the fan for the a/c in the car increases in speed. It goes away entirely when the fan is shut off. Knowing the noise is caused by the fan, we positioned the air vents so they would not blow air toward the phone microphones located above the front passengers. No change.
I called the Service Mgr at the dealership and he said he has never heard of problem.
Your thoughts?

Thanks for your response