One thought I have is have a resource library for math and formulas and sound concepts, like where people working on their systems can reference information on this site, like maybe how to wire a 5 pin relay for an amp turn on or like have a source that isn't a thread describing sealed vs ported and some basics to help people choose and get them to basic understandings and concepts when it comes to having a full car audio system. Maybe having resources for people to refer to on this site as they build and plan their systems will keep people coming back for that info. Knowledge is power...
Even when I designed I wasn't sure which direction I wanted to go with certain situations and would wind up reading info from sites to gather myself and figure how I wanted to approach certain enclosures. Some of that info would be 1/4 wave theory info, like about t-lines and horns, getting into some real sound math. I'm able to do that because I know where the resources are to help me clairify my thoughts by combing through data, that's what I'm suggesting here possibly to keep people's eyes here and genuinely help. But it could be basic sound or electrical or even more advanced stuff. Not a thread, but maybe an official resource data center or page or whatever for the site. Me being a box designer I think you could have every single math box formula on a page, including cubic feet /1728 inches and like how to get Fsc and Qtc of sealed box and the exact formulas for determining port lengths, things like that, simple transmission line enclosure formulas, explanations of t/s parameters, etc.