It looks like the image is distorted because it's being stretched the entire width of the mirror. Is there not a setting for the image to occupy 2/3rds of the width, like in the photo?
If you're determined to have a rear view camera/mirror and you aren't satisfied with the one you have, try one of these:
https://www.auto-vox.com/product/1700619789.html
The toughest part of the installation would be adapting the mirror to the Pantera's rear view mirror mount.