I recently purchased and installed the $142 auto dimming mirror from MazdaStuff.com. Three things I noted during installation: The plastic piece meant to cover the wire from the mirror mount on the windshield, to the head lliner, is too short. I added a small piece of foam tape and plastic to fill in the difference. The + wire to the electrical connector attaches to a blue wire/pink stripe. The green wire with black stripe has no power when the key is in the ON position. Finally, there are no clips along the pillar from the header to the dash. I used some other fasteners while being careful not to interfere with the air bag mechanism.

I also found the K&N Cold Air kit for $220. I installed that without instance. The pictures in their instructions are a bit hard to see.
Prying the plastic PCV piece out of the original intake hose is a bit tough. The bushing that gets installed from under the car, should go to the passenger side of the pre-drilled hole. Do yourself a favor... replace that horn with something louderwhile your under there.

I will be installing the cassette player shortly.

Automatically dims to reduce glare from headlights of cars behind you. Bright LED compass readout. Replaces the existing interior rearview mirror, Mazda part number 0000-8C-Z01 mirror, 0000-8C-L01 installation kit.

 

I have a 2008 Mazda 5 and also purchased the auto-dimming rear view mirror with installation kit. Here is what I found during installation process.

1. The plastic piece that hides the wire from the mirror to the roof liner is telescoping - in that it slides to the length necessary to fit and properly hide the wire.
2. I found exact same thing with wiring instructions. The Green wire with black stripe (in instructions) was completely dead (checked with voltmeter). I instead found a red wire with blue stripe that was 12V with ignition in ON position and connected to that.
3. I was able to actually avoid removing the A-Support plastic cover and instead fed the wire under from the roof liner to and then fed tucked inside A-Support cover - also careful to not disturb or interfere with the air bag.

Finally - the mirror auto-dimming feature and the compass both work great. The installation was quite fast and the instructions were good with the exception of the wire color.