How's it going, still haven't gotten to the bottom of the issue. Been trying to duplicate the feeling for Subaru. I have another drive with the shop foreman sometime next week.
What was the temperature in your area when this happened?
I believe it has to be around 50 degrees out, a little chilly, and you have to push the car to about 6K rpm and shift quickly to the next gear.
I made it happen today which I was trying to do shifting from 3rd to 4th and it was 53 degrees out. Last time I drove with the foreman, it was like 70 out and I couldn't get it to happen a single time and I did about 5 or 6 seriously hard pulls to try with him in the car. I really believe the temp outside has a lot to do with it which goes along with the other throwout bearing issues people have had, they get the TOB noise when it is chilly out before the car warms up. I have only gotten the clutch pedal vibration on cooler days.
Please let me know if your dealership comes up with anything and I will be sure to have my guys call yours to get to a resolution. I was even thinking of trading the car in over this but the foreman said even if something blows after the 50K powertrain warranty ends, my claim is as good as gold since I have documented the problem multiple times with SoA and taken a ride with him and he has documented our discussion if nothing else since I wasn't able to get the problem to happen with him.