A 28-year-old man was struck with a baseball bat during the incident, on Gain Lane in Fagley.
The windows in his car were also smashed in the attack, which happened shortly after 2.15pm on Thursday, May 17.
West Yorkshire Police today said the assault took place after the victim was approached by three men as he left a convenience store.
The men are described as Asian, with one thought to have had his hair in a ponytail.
They left the scene in a black vehicle – said to be similar in size to a Volkswagen Golf – heading in the direction of Leeds Road.
The victim suffered a hand injury in the attack.
Anyone with information is asked to ring Bradford District CID on 101, quoting log reference 13180237263, or Crimestoppers anonymously on 0800 555111.