When I recently got out of my car and closed the door, I heard something fall within the inside the door. At first I thought there was something rolling around in the interior door pocket (?), but there's nothing there.
Now every time I close the door, I hear this "thing" rattling. The door still locks, all the handles still work and the window still rolls down.
Any ideas what it might be?

 

no clue, pop off the panel and see what it is

 

How do I do that?

 

1. Disconnect the negative battery cable. (vehicle with power window system or power outer mirror)
2. Using a small flathead screwdriver, open the cap and remove the screw, then remove the inner handle cover.


3. Remove the inner garnish. (See INNER GARNISH REMOVAL/INSTALLATION.)
4. Remove the regulator handle. (vehicle without power window system) (See REGULATOR HANDLE REMOVAL.) (SeeREGULATOR HANDLE INSTALLATION.)
5. Using a small flathead screwdriver, open the cap and remove the screw.

6. Detach clips A from the front door using a fastener remover.
7. Pull the front door trim upward and detach tabs B from the front door.
8. Disconnect the power window main switch connector and power outer mirror switch connector. (LH) (vehicle with power window system or power outer mirror)
9. Disconnect the power window subswitch connector. (RH) (vehicle with power window system)
10. Remove the front door trim.
11. Install in the reverse order of removal.

 

Most likely it is change or something small that has fallen under the pocket in the door. There is a crack at the bottom and allows loose change and things of the sort to squeeze down there. Sucks.

 

I bought my '06 3 and thought that there was somthing in the door rattling everytime I shut the door. So I pulled it all apart and unless its something very small that I couldn't see there was nothing. still makes the rattle when i shut door but I can live with it. I do agree that it could be something that fell through the pocket cause when I pulled the door panel off I found a few of the previous owners things. On another note I gotta give it to Mazda I was really surprised of the quality of what was behind the door panel. My last 2 cars were GMs and all that's behind the door panels in both of them was a piece of 3 mil. sheet plastic and some sticky sealant to hold it in place. My first Mazda but maybe not my last.

 

That used to be a fairly common complaint and it often turned out to be nothing more than the drain valves at the bottom inner edge of the door. Some simply remove the plastic flaps, but personally I'd rather live w/the noise than have a greater chance of getting more water and dirt up there.
Temporarily why not use a bit of duct or masking tape to close them off and see if that cancels the noise? But again, I wouldn't recommend leaving it that way for long, just as a test.
The other problem known in the '04's and 5's is the window hardware coming loose where it attaches to the regulator, but you shouldn't have that problem in an '06. Who ever thought it would be a good idea to use plastic screws there can think again.