I had a horrible buzzing/rattle coming from the passenger side footwell - I thought it was just crap in my glovebox or the box itself, but I removed the whole assembly and it wasn't that.
Low and behold, it was the plastic blower motor housing. I contorted my way upside down under the passenger side dash and took out the blower motor to give it a good talking-to. (Unplug the electrical plug, loosen 3 screws, drops right out).
Looks like this:
Flip it upside down and you'll see a little plastic panel on it:
To backtrack for a second, knowing that I had to fix a rattle, I purchased some sticky-backed black felt at a local craft store (Michael's). It came in thin 9x11in sheets and was like $2.99/ea. Excellent for stopping vehicular rattles.
I popped open the little plastic panel with some body panel tools and wrapped the edges of the door in felt. Because the felt is so thin, the panel clicked shut again no problem.
Just incase it wasn't just the panel rattling, I put little round pieces of felt (I cut them) on both sides of the screw holes, where the screw touches the plastic and where the plastic meets the rest of the housing.
I reassembled it and hoped for the best. The rattle was constant before and in 2 days, I haven't heard it at all, so I'm guessing this solved it. My sanity can now slowly return.
