Most newer cars already have a display showing you how efficiently you are driving. Usually this takes the form of a digital readout showing you miles driven per gallon of gas over 2 time-frames: short term (instantaneous) and long term (average). Wouldn’t it be cool to add this feature to older cars?
For our demo, we used an OBD extension cable and shorter wire to the NeoPixel. Alternatively, we could have plugged M2 directly into the OBD2 port and ran longer wires to the LED display. For the test drive, we just stuck the LEDs and M2 to the dash with double-sided tape.