Thanks! I was suspecting the motor mount. But the car is so smooth when I drove it and the engine does not move that much when I shift into reverse. Engine does not move when shift into drive. So I am not leaning towards a bad mount. But I will get it checked out soon.

Also, the sound is like grinding when car is cold. I can also hear a slight grinding kind sound when shift out of reverse when the car is cold. When the car is warm, shifting out of reverse has no sound at all.

So besides the sound, is the kind of impact I feel normal? Thanks!!!!