i'll spill the beans as i've given up hunting now as everything is too big or too expensive
basically, you know the led tshirts? the sound reactive equaliser ones with a panel on the front?
well the plan was to remove them and stick them to the mirror covers on the sunvisors, taking power from the light and being able to be slid away. activated when the visor flips down....giving 2 displays on the visors when down. pimp.
volume adjustment for the pickup hidden in the door under the bottom speaker
parts cost about £20, scene points for innovation 9/10
i'll suss it at some point, just a hassle of finding a decent display...tried most of them now got bored and moved on.