Cars of any colors look the same dull in darkness; the beautiful graffiti ensembles covering thousands of square metres of walls in my native city are nothing but obscure shadows at nighttime...
My idea is inventing a special luminiscent sort of car-dye spray that would make car bodies and graffiti pictures gleam at night, making night driving safer and enhancing graffiti with a fascinating aureole in darkness.
Don't you like this idea?

PS: I can think of thousands ways of using this luminescent dye-spray for decorating my house for CHristmas holidays