I had purchased a tablet that I wanted to be able to charge in the car, but was unable to find a suitable car charger that would work with it. I then wanted to use a power inverter to charge it, but they are all big and bulky. I then had the idea to add a 120v power outlet to my console. I had a little change holder in front of my shifter that did nothing except collect trash. So, I modded it to house a 120v power outlet.
Step 1: Find a Suitible Place for Your Outlet.
Find somewhere that is convenient and not needed to place your outlet. The change holder popped right out and just barely fit the power outlet. I took the outlet cover and cut it down to follow the contour of the change holder. I then painted it black to match the interior. I then took a 120v electrical plug and wired it to the back of the outlet. Basically, now you have a 120v wall outlet with a extension cord on it. You could also just take a extension cord and cut one end off and wire it up the same way. I just happened to have some spare electrical wire and plugs laying around.
Step 2: Find a Suitable Power Inverter
I already purchased this one a while ago. It was small enough to hide under the center console. I plugged it into the wall outlet and then connected it to a 12v extension cord. I have a power outlet I never used in the ash tray. I was able to route the 12v extension to it from under the console and plug it in and have the ash tray closed so I never see the wires. You now have a working wall outlet in your car.
Step 3: Optional Step: Add Relay
The power outlet in my ash tray did not cut off when the vehicle was off. I purchased a 12v accessory relay from the local auto parts store and wired it inline with the 12v extension. Then i found a accessory power line that I could tap into and wired it to the relay. This way, I don't have to worry about unplugging the power inverter since it will now be controlled by the relay.