How to make a car compatible Wii.
This is a very simple tutorial how to make your Wii car-compatible.

Step 1: Making a Fitting Power Supply

Simply use a car 12v power adaptor. Put this together with the whithe things which are being connected to the Wii.

Step 2: (recommended) Softmodding Your Wii

I highly recommend to softmod your Wii. A softmodded Wii can load games from USB. In a car we normally do not have all our Wii Discs.
If you want to hack it ask Google for "Wii Homebrew". You can choose all games from USB and do not need to change discs while driving.

Step 3: Making an Adaptor "Wii to Car Monitor"

For getting picture of the Wii to the monitor you need to make this simple adaptor. You conntect the cable of the car monitor to the Wii cable with such female/female plugs

Step 4: (optional) Making a Sensor Bar Into the Monitor

Logically we want to use the Wiimotes(Wi controllers) too. But the sensor bar in a car?... Simply build it into your monitor!

In this step we need soldering equipment.
Screw up your monitor (1). Then drill 2 holes in the upper or lower part. Put in there IR leds (2). Connect these to a voltage regulator (3). Connect this Construction to your power input (4). Finally you should have IR leds which are working without any specian Wii cable for the sensor bar.