The Prius was due for an oil change, so I added the LiquiMoly Ceratec in the process. The instructions say the bottle (which is 300 mL) can treat 5 liters of oil. That's a 6% solution. And my engine holds just under 4 liters. So I put 240 mL into the engine oil.
I also added some Ceratec to the transmission oil. The instructions specifically say not to put it in transmissions with wet clutches, or in clutch style limited slip differentials. The transmission in my Prius doesn't have any clutches in it. So it should be fine. I decided to add 200 mL (a 5% solution) to the transmission.
Now I just have to wait and see what the fuel economy data looks like.
Also, a side note about the pizza pan wheel covers. I haven't checked the tire pressure in awhile, because the pizza pans don't have access holes for the valve stems. And as a result, the tire pressure got pretty low. That's on me.