Thank you everyone for your comments and suggestions.
I plan to make more measurements tonight using your suggestions. In the meantime, I have some more graphs from my measurement session on 5/4/2020 that I hope you find interesting.
These measurements were made with the No-Rez installed in the speakers. The mic was on a mic stand at ear height with the arm extended all the way out.
In this measurement, the right speaker was forward facing with only a very slight tow in. The mic was placed in 3 positions: center (seat), left (mic swung to the left of seat about 2-3 ft), and right (mic swung to the right of seat 2-3 ft). The right speaker was pointing almost directly at the mic in the right position.
When I saw the right position graph, I thought that this indicated that I needed to tow in the speaker so that it pointed directly at the seat. I did that and took another measurement.
I was expecting a better match than that. Here's the original forward facing graph vs. the towed in graph, both with the mic at center (seat).
To me, the best measurement was made with the mic to the right of the seat, with the speaker pointed directly at it (forward facing). I think I have more experimenting to do with speaker placement.
More measurements to come. Should I create a new thread for the measurements, or leave this subject in this build thread?