That technique is actually used in cars quite a bit. It is used for steering wheel switches so only one wire is needed for 3 switches for example. They make a multi tap divider out of 4 resistor so each switch sends a different voltage. The rear window switch in the door of my C230 uses this system to detect rev, off, 1/2 fwd and fwd using only 1 wire to the window controller.

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra