I have an 04 enthusiast 6spd w/4k miles and I think I'm experiencing some serious gear whine. Well, I've been in a S2000 with an aftermarket gear set and it made a similar noise. However, it made the noise on deceleration while mine makes it on very light acceleration from 60-80 mph (in 5th or 6th). It sounds like a whistling sound from the rear at freeway speeds. It can be loud enough to hear over the radio at moderate volumes. Any suggestions? Thanks.