As the title suggests, I would like to capture the position of a car turn signal at the neutral, up and down positions. The turn signal exterior would be left unaltered inside the interior of the car (the car is to be used in a motion simulator, hence the need to preserve the interiors). In addition to this, devices such as infrared proximity sensors that measure the distance of the turn signal in order to determine if it is up, down or neutral are not ideal.
What are some good methods to use an Arduino to receive turn signal position data, while maintaining stock exteriors? As I understand, the turn signal uses a switch to close/open required circuits in order to activate lights. What sensor could be used within this circuit in order to determine turn signal position?