2004 impala mirror

I'd like to change the standard mirror which came in my wife's impala for one with outside temperature and compass. What other parts would I need, or is this essentially a dealer only deal, and I should just buy an after market type mirror and go from there? Thanks.

i know you can do this, but you would have to buy alot of censors and crap like that.

You would need a temp sensor located in the front of any gm car or suv that has one it is a two wire deal green/white black. just run a new wire out to it and put it in front of the radiator.