I have pretty severe back issues. injuries over the years have wreaked their havoc. Ergo, I see a physical therapist regularly, and have a regimen of daily exercises. It all keeps me going.
My 5th gen Subaru was giving my back a lot of trouble. However, it showed up in my right leg. After an hour on the road, my leg began to ache, and nothing seemed to help. This went on for a long time, even though I changed positions, amount of lumbar support, etc.
One day, i mentioned it to my physio. He asked me to take him to my car, and sit in the seat, while he viewed my positioning from outside. First thing he did was to get rid of all lumbar support. Second thing was to have me adjust the seat and seat back angles, and finally, he changed my distance from the controls, just a bit. I drive a 6MT, so that last issue is critical for a short guy, like me.
No more pain. The following weekend, I drove for 4 hours, and it was like magic. I suspect when one has total control over angles in a number of different planes, it is difficult getting it all to work together, correctly.