One things about my Toyota Prius that always bothered me was that there were no USB ports or Cigerette lighter outlet that were always on, meaning, powered when the car is off.
I finally decided to do something about that and installed a Quick charge USB 3.0 outlet.
Now, I can charge devices through this USB port while my car is turned off. The best part is the switch on the outlet so I can turn it off when needed to not draw power from the battery.
Installation was straight forward, I used one Add-a-Circuit Fuse Adapter to draw the constant power then wired everything up.
The best part is now my Android devices now all Quick charge!
After removing the existing Cigarettes lighter panel and drilling a hole I was ready to install.
See the links below for the products I purchased.