I am kind of anal about this kind of stuff too.
When ever I buy stuff, things, etc. whatever, I take close-up digital pics and put it under that stuff's folder called "data" or "info".
Then when I want to reference it I just go to, in this case my 370Z folder and open my tire pressure pic... it's inside the door (in the manual too), also inside the door is the manufacture sticker which is good info to have on hand!
Saves a trip to the garage!
Mine is a base model...