Investigator Scott Sandford alerts us to this pathblazing study: “Polycyclic aromatic hydrocarbons and the unidentified infrared emission bands: Auto exhaust along the Milky Way,” L.J. Allamandola, A.G.G.M. Tielens and J.R. Barker, Astrophysical Journal, vol. 290, 1985, pp. L25-L28.