In short, I really disliked the bose stereo system in my 2017 Mazda 6 and did a full custom install to replace it. I even put a new head unit in without removing the factory one. It's been working great for over a year now and I documented the build here: http://johnstechpages.com/node/12 . It really was a process that took around 4 months from start to finish. I think it will help anyone who's thinking about doing something like this. Here's what it looks like: pioneerdeck_installed_small.jpg

Thanks,
John