Another vote here for checking the sway bar links. I've got a 2004, and every time I'd go over a bump it sounded like I'd lost a motor mount. The clamps that hold the sway bar to the frame have a hard rubber coating that will wear off as the car gets use, allowing the sway bar to smack against the frame. It's a dealer part, about $45 for both sides if I remember correctly.

I've got another rattle in the dash, passenger side, but I've got to replace the heater core before it gets much cooler so hopefully I'll find the source of that when I pull the dash out. I foresee much alcohol in my future.

I'll post with that info after I finish that job.