Police have reviewed video and said a white 6 series BMW appears to have been on the bridge at the time of the accident and may have important information relating to the crash.
Police could not say if the BMW was involved in the accident.
Two young men, aged 20 and 21, were killed on November 28 when their vehicle, a Mazda 6 heading northbound, spun out of control and crossed into the southbound lane.
The car collided head-on with a West Vancouver Transit bus. Police said high speed was at least partly to blame.
The two young men, who were both from Richmond, had to be removed from their badly damaged car by the jaws of life.
Four people on the bus, including the driver, were treated in hospital for non-life threatening injuries.