Coming up on one year of ownership, I'm right there with you. I still consciously do what you did on your test drive, trying to find a solution that I know does not exist. I cannot drive with my legs squeezed together...they naturally spread a little when relaxed. I actually tried again today. Maybe I could zip-tie them together.
It's weird...I am not a big man. These seats are just so small and narrow. I'm not sitting in it...I'm balanced on top of it.
I might visit an upholstery shop just to talk to them, but I don't know if they are truly seat-fit experts. I cannot afford to take the financial hit and find a different vehicle.
Good for you for taking your time with this. I wish I had.