I had it twice... both in cold whether and stop and go traffic. I found that the idle dropped too low when you ease on the brake and let the car roll back a little and it eventually stalled; it's very hard to reproduce.
I took it to the dealer and they couldn't find any error code, the TCM is...
Removing the door panel is not as difficult as someone mentioned, here's the instruction in Japanese and wish it help:
To enlarge: http://mazda3forums.com/gallery/albums/userpics/10504/DoorPanel.jpg
The product from DGM is very good; I'm not a big fan of carbon fiber but after browsing through their catalog, I'm impressed! Tell Amie not to worry, the quality of her products stand by themselves.
Check out http://www.mpvclub.com , great resource about MPV and really friendly people. I got a 2003 MPV (ES/GFX with $2500 rebate) 2 months ago and the whole family love it. We pick the MPV because it's the only true mini van and has the best handling within it's segment.
The only known issue...
I went to a couple other Mazda forums and this is the first AC compressor problem I come across.
The Mazda3 is new so almost all parts are in national back order. I try to order a underhood insulation for my GS (the underhood insulation only come with GT) and it's also in natioanl back order...