Yeah, getting the thermomether through the firewall is absolutely the hardest part. That's one nice difference with the 2006.... the temp. display is on the dash and not on the mirror, so you only have to hook up power to the mirror and you're done.

 

the panel on the inside roof, does that have to be taken off? how do you see and get under it? My dad doesnt want me to do any kind of work to the car that will ruin the appearance of the car and if i do he will KILL me. i would like to know if the roof will look the same after the installation process.

 

Go here for a really good walkthrough on how to install the auto-dim mirror. You'll have to pull the kickpanel and A-post from the driver's side of the car to access power wires, and to run the wires for the mirror. The walkthrough is for a homelink mirror on a pre-'06 car, so they had to run the temperature sensor too. That right there is the majority of the work you would need to do, however if you have an '06 then it should be really easy. don't worry about it being a homelink mirror if you have a standard one as the power needs should be the same.

 

Thanks for the instructions. I have an 05 so I will have to do all that work. I was not expecting the installation to look like that, but it is something i am now willing to attempt.

 

Not a problem, I'd just been reading a similar thread on the mazda3forum so I was thinking about it. I actually had the dealer install my mirror, but that's just because I negotiated the install for free with the purchase of the car. If I'd had to pay them I would've installed it myself.