My car, when idling, vibrates horribly. If I place it in neutral, the vibration stops or lessens greatly. My thoughts are motor mounts. My car doesn't have that many miles on it, 138,000. At least I don't think so. I purchase it new and have taken great care of it. Is there any chance this problem is the transmission (it does shift hard sometimes too though) instead of the motor mounts. Thank you.