A 23-year-old Willagee man can remember little of an incident in which he was bashed and had his car stolen after he stopped at traffic lights in Maida Vale.
Police say the carjacking happened some time between 8pm and 9.15pm on Sunday, March 2.
The man had stopped his 1997 white Volvo sedan at traffic lights at the corner of Hawtin and Kalamunda roads in Maida Vale.
He was bashed in the head several times and dragged from the car by a man who stole it.
The Volvo was found at about 10pm on Ridgehill Road, Maida Vale.
The driver was taken to Swan Districts Hospital for treatment for head injuries.
The offender is described as being in his 30s, of solid build, balding and with a bushy beard.
Anyone with any information is asked to call Crime Stoppers on 1800 333 000.