Aaaack!
Too confusing . . too many different wiring schemes between all the manufacturers as well as the car makers. For example, the E36 has at least 3 different wiring setups that I know of, and the way MB Quart sets up their crossovers is not necessarily the same as other brands. You really have to take everything on a case by case basis. Plus, I didn't mention this to Numark, but there are at least 3 different ways to set up his system, I just gave him the most common configuration.