I have a 01 SE Auto, and I am having a slight rattle/ vibration while I am in Drive and sitting still. I can feel it under the floorboard and in the brake pedal. It goes away when I let off the brake and pull away. I thought maybe a bad driver side axle, but I don't know

 

Is your car missing? If not, then I would lean toward a bad motor or tranny mount.

 

no, not missing. I was kind of thinking about that too. Wouldn't a bad motor mount continue to vibrate at speed though?