Yesterday, I spent several hours playing with the system. I have many autosound 2000 test discs, and used those. One of them, and I don't remember right off which one it was, helps set up imaging. Many tracks of both noise, music, voice and tones, that go from L to C to R. Before I started playing with the t/a, there was no C. But I adjusted the t/a manually, based on preliminary ball park measurements with a tape measure, then just by ear, and can now definitely place performers on the dash in positions that I never did before. This is only on good recordings though.
Then I set the preset eq to powerful for the time being, and it sounds way better than it ever did with my alpine hu.
Next I will try to do what Jeff said above about removing the head rest cushion, and suspending the mic in the air. Right now t/a is on custom so I won't lose what I did when I do auto eq/ta again.
Is there anybody in the Pittsburgh, PA area that is willing to help me out in person? I have never even heard a vehicle with all of the equipment in it that Jeff has in his signature above.
Thanks so far everybody, and keep the ideas coming....