I was going to link to that 71 in the DIY forums, as I am a member on there too....if you look, I even had replied to that very same post
Anyway, I will be one person to ask that you AVOID 6x9 speakers. They are pretty much worthless. 2-way component sets are more versatile as far as mounting options and will deliver much better sound quality than the "by nines".
Oh and dont ever mount any speaker other than a sub in the rear, as this destroys any sound staging. Bass should come from the rear and mids and highs from the front.