At highway speeds I'm hearing a fluttering sound (could be tire noise) and an unpleasant whine out of the back end. Anyone else have this experience? Mine's an '05 with about 29,000 miles. The car's otherwise fine, but these too-loud noises are a definite detraction from the driving experience. Is this a) just the normal road noise of an RX8 b) a symptom of tire wear (they're the originals) c) something more ominous, like the differential going South?

 

Mine was a high-pitched whistle/whine. New diff under warranty.

 

I'm going in for the 4206F Emission recall today and I'll ask them to check out the diff. Thanks.

 

Similar sounds as you describe - mine was the original equipment Bridgestones on my 04 (at 18K miles).

 

Have you ever changed the fluid in your rear diff?