Strange vibration in vehicle body
 

I have something weird going on. When I accelerate I have a vibration into the body of the vehicle at 20MPH. I can feel it in the foot rest on the driver side. After 20-25MPH the vibration disappears. When I switch to manual mode I get the same vibration at the same speed whether accelerating in 2nd or 3rd. Do you think this is a transmission issue or more likely a bad torque strut or motor mount?
2010 CX-7 2.5L