There are after-market sensors you can get for cars, for example, reading the oil temperature. You basically screw a sensor in and it has a little sender that goes to an electronic gauge.
Would it be possible to instead run these cables to an Arduino and infer the same information? I imagine so, but how would it be done? A lot of experimenting or would it be relatively straightforward?
I want to have a custom interface for this information combined with a Raspberry Pi and the auxiliary video input to a car stereo's display.