What is the test for reasonable suspicion in a vehicle stop?

This reasoning is, moreover, routinely given effect when courts uphold vehicle stops on reasonable suspicion where the police had some information describing the car they were pursuing, but not enough to identify it precisely. See, e.g., United States v. Rose, 731 F.2d 1337, 1342 (8th Cir.) (yellow car driven by black female), cert. denied, 469 U.S. 931, 105 S.Ct. 326, 83 L.Ed.2d 263 (1984); Luckett v. State, 259 Ind. 174, 284 N.E.2d 738, 741-42 (1972) (police "did not have probable cause to stop every green automobile with an 82J license prefix" in a given area, but they did have reasonable suspicion). A good but imperfect description narrows the range of suspected vehicles sufficiently to permit the legal conclusion that reasonable suspicion exists with respect to each car remaining within the suspect range.