This bizarre tale comes courtesy of the Associated Press:

LOS ANGELES — Police following an anonymous tip sent by fax to a television station
found a dead woman in the trunk of her car Saturday, and are looking for the sender and two men alleged in the message to have been involved in the crime.
Officers discovered the body in a Valley Village neighborhood in the San Fernando Valley soon after being notified by KTLA-TV staff members about the faxed letter, Officer April Harding said. The sender described himself or herself only as “someone trying to help.”
The sender wrote that a woman was killed Feb. 28 and that her body was in a black trash bag in a car. The sender said the car would be within a 2-square-mile area of a specific address; police found it several blocks away on a shady residential street facing the 101 Freeway.
“She should be reported missing by her family,” according to the letter provided by KTLA.
The sender also named a suspect in the killing and another man who helped the suspect clean the car.
The fax included the victim’s name, but police did not immediately release it or the cause of her death pending notification of her relatives and an autopsy.
The Nissan sedan was registered to the dead woman, Sgt. Sharyn Buck said.
“It’s a sad, sad scenario,” she said.
Investigators were trying to track down the sender and the people named as suspects in the fax, Buck told reporters.