LeMans 24hr racebikes have been using luminescent panels for their race numbers for years, along with little coloured ID lights on the front nearside of the fairing - two greens and a blue, say - to enable the pit crews to identify which bike it is that's coming in for fuel or tires at night. I've always thought this a really cool look, and have been waiting for it to catch on among sportbike types for ages - but so far it hasn't.