To build your own G-Meter in just one minute, you’ll need a CB220 module and a Plug-N-Play LCD. Full instructions here. Videos after the jump.
It seems like my car can handle up to about 0.4Gs at the most. You can see in the video when the vehicle is decelerating, the Gs are negative. You can modify the code to have a calibration of your G-Meter by noting the voltage output when the G-Meter is at a complete stop