1997 Plymouth Breeze vibration

My 97 Plymouth vibrates when not moving. I feel it mostly on the steering wheel. The vibration is different in each gear, in park the steering wheel vibrates but not real bad. In reverse it hardly vibrates,very little. In neutral it vibrates about like it does in park. In drive it vibrates a lot, steering wheel and I can feel a strong vibration and noise around the dash area all this with the car not moving. I have taken the car to a mechanic and he said the motor mounts looked good but mentioned a tune up so I replaced the spark plugs and it made no difference. While driving the steering wheel does not vibrate nor does the car as best as I can tell. The worst vibration is in drive with my foot on brake.
Thank You