I had an idea for light up knobs whilst sat in a car the other day. A lot of cars have knobs for the heater, etc which have a translucent pointer, suitable for underlighting. They are usually fairly flat, broad knobs but there’s loads of different types and sizes, when I get a chance I’m going to nip down to the local scrap-yard and see what I can find. Most cars have several matching knob.
Most of the “car burial grounds” I got parts for my car from charged by the kilogramm for electronics and other small stuff and by randomness for hoods, doors and the likes. The paying by kg part was always fun and pretty cheap though.