Hi Kano.
Out of frustration, i decided this morning, to Google "Humming noise from the rear Nissan 350Z" and was happy to see you posts and responses. I am from South Africa and also have a 2004 350Z. I immediately signed up to www.350z-uk.com in order to write to you. I have the exact symptoms you described. I suspected it was a bearing but was not sure whether it was the right or the left rear. I went to Nissan and requested a rear bearing. I asked whether it made a difference in purchasing either a right or left and was told they were the same. After receiving the bearing i noticed "RR bearing" (Right Rear?) on the box. They are different aren't they? Right Rear and Left Rear? Or are they the same? I haven't replaced the bearing yet and now after reading your posts, i think i should just replace both sides.
Regards
