Mine does vibration between 2800-3200rpm (not every time). If I put my hand on the hand brake lever its gone. I have checked already almost everithing, and seems that it comes from handbrake drum. But it contradicts the fact that it comes every time between the above rpm range while the drum is running with differnet speed in every different gear.
Surely comes from the drive system as when the car is in neutral there is no vibration.
Do you have it also when the car is standing?