Either factory (if it was available) or aftermarket. The wife wants this for Xmas and I have absolutely no experience with it. I don't know anything about these, so I don't know which ones are good, who to get one put on by, etc. Was there a Mazda one, and is it worth having the dealer put it on? I don't want some 15-year old hacking up my wiring like Best Buy "back in the day" when I last had electronic stuff put in a car of mine, so how do I tell if the install place is good? Thanks in advance!