Why don't you document the install YOU do, and show us how your choices influenced your results. Especially so the OP can compare the pros and cons of each method.
If all you can do is get pissed because they cost extra, give us a component run-down of what YOU used, and explain WHY you feel so strongly against spending the couple hundred extra to cut the wires off factory connections and do it your way.
--Otherwise, you're just another angry poster blurring the line between a post that HELPS and a post that distorts and creates argument.
On top of this, the time, research and risk taken (and believe me I've learned) is NOT worth the hassle of working another day or two at work to cover to difference, especially when you can pop BSW speakers in without any questions.
The fact that I started out at 16 building custom audio systems and had probably the best SQ system in high school, done DIY, by myself over weeks and months gives me an interesting view on your thoughts without any sort of validation to your claims, especially on a e46. Little things matter, and something like a custom setup requires those little things be documented if your going to say your right.
Where's my proof?
Anyone ever hear of a JL W6? I got the same SQ out of a custom driver setup powered by a TC Sounds TC9 hybrid off a 750.1 w kicker amp and blew everyone away that dared to enter with the clarity of my 2-way active setup in the front (no rears) run off a 4-channel US Amps. I spent $1500 DIY at the time for the whole thing, incl sound deadening and wiring.. far less than other peers who ended up with a kicker square sub and a shitty touchscreen double DIN.
Where are your bragging rights that you did the same in a e46?
The thread I posted has FAR more details useful to this topic than any of your posts.
The anger in your post seems to only bring this thread further off-topic and underline your character rather than something useful like your own DIY thread.
Please try to focus less on yourself and defending the fact that you're right in your posts, and try to put some more effort into helping the community and more specifically the OP, or we would appreciate that you just pass up the next opportunity for everyone's sake.