A man has died after being stabbed before crashing his vehicle into another car in west London.
Detectives do not believe the victim was killed in a "road rage" attack, and suspect he was involved in an earlier altercation.
The 26-year-old was found in a vehicle suffering from a stab wound outside West Ealing railway station.
Detective Chief Inspector Neil John said: "We believe the victim was involved in an altercation 100m from the railway station on The Avenue.
"This is a busy street with a number of shops and restaurants and if anybody was in the area and saw something, no matter how small, I would urge them to contact police."
Police were called to the area just before 1.20am on Sunday and the man was pronounced dead at the scene.
It is believed the victim was injured before his vehicle was involved in a collision with another car.
Scotland Yard said the man has not been formally identified but inquiries are under way to find and inform his family.
A post-mortem has yet to be carried out to determine cause of death and no arrests have been made.
Kiran Ramachandraiah, who lives in a block of flats overlooking the scene, said he woke up at about 2am to see medics trying to revive the victim.
"I couldn't see the person," he said. "He was completely surrounded by police and paramedics."