Long time casual car audio enthusiast here. I got into car audio upgrades way back in high school (25+ years ago), did a build in my first car after college, then kind of got away from it all. Fast forward to about a year ago, bought my oldest son his first car, a beat up '98 BMW M3 with 399,000 miles on it, and we decided to make it a fun father/son project. We completely overhauled the audio and installed our own system, pictures of which I can put on a build thread if there's interest. Then his car was so fun, that I decided to get myself a nicer, collector quality version of the same car. But I had to tackle the audio, all while leaving it un-cut and able to reinstall the original stock system if someone wanted it that way. So we did another complete build on a '99 BMW M3, build thread on that can be created too.
Now here I sit, about to pick up an '06 M5, and looking at what to get for that build, and I decided this forum looked like the best place to be. Thanks to all of you for creating a great resource here, I hope I can contribute and give back for all that I'm learning here.