cornerhungry

My wife drives my allroad most of the time but I needed to borrow it to commute to work this week. one of my favorite things about this car is the peppy motor. I took it out this week, put the pedal to the floor and
it took off as usual but i noticed a vibration that wasn't there before. It only does it on hard accelleration. It has about 45k miles. any thoughts ? or anyone else have any expereince with something similar ?

thanks all
Mike