West Valley City police Capt. Anita Schwemmer said investigators impounded Josh Powell's minivan on Thursday after obtaining a search warrant.
Susan Powell was last seen at home on Dec. 7. Josh Powell told police he saw his wife about 12:30 a.m. as he left with the couple's young sons for a winter camping trip on the Pony Express trail west of Salt Lake City.
Josh Powell, 34, has been called the sole person of interest in the case, but has not been arrested. He moved away from Utah weeks ago to stay with family in Washington state.
He was back in Utah on Friday to prepare his West Valley City home to sell or rent.