Citroen DS is an ordinary Citroen car issued to Shirei for official trips outside of A.E.G.I.S. Headquarters. It has an emergency pistol in its glove compartment. It was used when Shirei brought Shun to the secret A.E.G.I.S. headquarters for the first time; and when he and Keiko were chased by the monster #1 Hakosuka.