What is the test for consent to search the vehicle of a suspect?

United States v. Analla (4th Cir.1992) 975 F.2d 119 is instructive on the issue. In that case, officers approached Analla while he was at a phone booth and asked to see his license and registration. Analla acquiesced and waited with the officers while one of them checked the license over the radio. During the check, another officer arrived and advised Analla he fit the description of a murder suspect. Analla then consented to a search of his car, which led to the recovery of the murder weapon and other incriminating evidence.