Hi there.
I want to thank you for this excelente tuto. This was THE ONLY ONE that worked for me.
I've been searching for the solution for many days, removing and reinstalling nvidia with a low bandwitdth connection. I think the point is the xorg.conf and display manager configuration you found on offical docs.
Now I have nvidia running on my kali thanks to you.
Spread the word and make this possible for others.
Very nice, man. Good job.