Purpose of grid drawings 3

[Azzazil]

Unfortunately I was not able to make this question on thread Link, since it is closed.
I am curious why in automotive there are drawings with grid and without any dimensions on them?

 

[Azzazil]

Thanks for explanation, I manage to find through links on my first picture and it lead me to document "reference-point-system-rps-vw-010-55". Here is Link.