I had my old car set all the way to the right. It was a 03-07 Honda Accord, the tweeter shoots up to the windshield, and H100 never worked right. In fact, Pioneer's auto eq auto also didn't work without manually adjusting time alignment afterward.
What kind of car is it?
Do you select a curve with high frequency roll-off instead of a flat response? I am also into that problem with my new car, though with a PXE-H650. Still an Imprint processor. If I make it a flat response the right side would take over. If I select a curve that the top of the frequency response rolls off, the problem solved. Want to try and see?