MatthewMiller

One small additional suggestion: if you have the car in neutral/park, not moving, and you can't replicate the vibration by revving the engine to the same 2000rpm, then you have ruled out the entire engine, flexplate, and t/c. If one of those things were the culprit, you'd feel the vibration at the same rpm regardless of road speed or gear selected. You've noted that if you drop the trans into neutral while rolling at the problem speed the vibration goes away, but that doesn't rule out the u-joints. When they go bad it usually only is felt when power is applied to them. I agree that it's still most likely a u-joint. And I agree with confab that they can be bad without still being easily seen during a visual or shake test.