Fiore's white Mercedes-Benz was found abandoned in a parking lot beside a Trader Joe's along the 8600 block of Santa Monica Boulevard in West Hollywood on Wednesday.
Powell says detectives found mud stains, weeds and twigs on the car's undercarriage, which could indicate it went off-road.
Fiore's mutilated body was found Aug. 15 stuffed in a suitcase in a Buena Park trash bin. Her teeth and her fingers had been removed to delay identification, but the coroner was able to identify the body by the serial number on her breast implants.
Ryan Jenkins, a contestant on VH1's "Megan Wants a Millionaire," was found dead of an apparent suicide in a British Columbia hotel room Sunday.
The Associated Press contributed to this story.