I have the exact same thing. (EVO X MR)
5th / 6th gear vibration at 2100 RPM only when letting of the gas.

It wasn't always like this. But it's been going on for a few months:

I just reblanced the wheels and had an alignment done. It improved, but it's still there.

Someone told me, new tires might help ?
Shouldn't we worry about that vibration spreading to other areas?

 

Down shift
When I'm in 6th and let off the gas, as soon as revs drop below 2500 I downshift to 5th. With the exception of 2 to 1 shift, I make almost every down shift between 2000 and 2500. Unless of course if its to get more power and accelerate, thats a totally different shift point. I find our engines tend to bog down if I let the revs drift below 2000, with the exception of 1st gear.

 

? I don't hit 6th until 200km/h

 

Bringing back an old post but my car has this issue at the same rpm. Any ideas on what it is?

 

Try what sstevojr (above) said to do first.

 

Yep, always had this.

Rich

 

I was JUST about to ask about this. I finally managed to get a set of wheels on the car that i balanced my self, unlike the abused sets i got with the car. Yes, i know, i should have taken the time to do it properly before swapping the winter wheels on the car, but i didn't, and had to live with vibrations from imbalanced wheels all since i bought the darn ride. Nothing huge, but enough to obscure these "coasting" vibrations. Now that those are gone, the coasting vibrations were starting to get me worried, thinking i had a drivetrain issue, and i actually came here to ask you guys if you thought it could be a prop-shaft, or a U-joint.

At this point i guess i'm relived, and will just go away.
Not to worry, i'll create new daft threads shortly, asking more dumb questions. I'm just researching things ahead of time.
Anyway. Thank you. ALL of you. Huge thanks.
B!