Given the bulky nature of 12volt adapters for vehicles, I decided to integrate a USB power outlet in my 2010 Prius III. Although this mod is specific to my car, it can be applied to many cars, trucks, RV's, boats, ect.
Step 1: Finding a location for the USB power plug
In the 2010 Prius III there is an unused outlet next to the 12volt aux power in the front center console. I disassembled the center console and removed the plastic housing of the blank outlet and the 12volt aux.