Overfilling rear differential with 5 Qts?

It's an Automatic. It services itself automatically. No need for drive input other than selecting S-mode select S-4, while double pushing the the start stop button and moving the passenger mirror up and to the left at the same time all while the 4 ways and service brakes are applied.

 

I prefer to make my own:

 

Yes but you must remember to put the fill plug back in or it will only be half full.

 

Differential. It’s named that because it’s meant to take different fluids besides what the manual says. Brake fluid and coolant provides maximum torque