10,000 miles & no buzzing here!

 

Most definitely the shifter. You can manipulate the buzzing by putting pressure on the shifter (left, right, fore, or aft). For example, if I am in 2nd running up the tach and it starts buzzing, all I have to do is gently nudge the shifter back towards its stop and it will make it buzz if it isn't buzzing or stop it from buzzing if it is buzzing. I am planning to take the car to a different dealer than I normally go to since my dad knows all of the service people and they will hopefully be more willing to help me with this than my local dealer I usually go to.

 

The sport shifter has a heavy weight of sorts on the shaft for the reverse lockout. if you grab the shifter by the boot you can feel it on the drivers side of the shaft. When buzzing occurs try this and see if it goes away. The ball and socket @ the end of the shifter is a rather tight set unit so I would think it odd for the lower part of the shifter to be causing this issue unless the cable assy is misaligned... (ya never know)

 

I was actually looking at that the other day. I unsnapped/velcroed the boot and snugged the 4 hex bolts just a tad. It seems to have slightly reduced the buzzing. I just need to take it in and have them look at the remaining rattles that I have pinpointed.

 

I have the exact same conditions and it has gotten worse. I used to only notice it when I pushed the lever slightly forward in 5th but now it does it on its own. I haven't been to the dealer yet but am curious if anyone else has found a solution. Mostly noticed when I let off on the gas slightly.