That would be the front of the car, hopefully my wonderful image makes some sense.
The tweeters (25NFA) will be in the A-pillars, aimed slightly toward the windshield. The green lines are on-axis.
As you can see, the listener is almost 90 degrees off-axis from the tweeter on his side (red line)
It is generally recommended to use the straight line from the speaker to the listener to calculate the required time correction, but wouldn't it make sense in this case to use the reflected blue lines, which are presumably more representative of the distance travelled by most audio waves? Or is the first wave reaching the listener always the point of reference for time correction?
Thanks in advance, figuring out all that stuff is a lot of fun.