The victim, named locally as Kenny Reilly, was attacked in the Ruchill area of the city late Monday evening.
He was sitting in the passenger seat of a silver BMW at traffic lights on Bilsland Drive about 10:30pm when the incident took place.
In what officers believe was a “targeted attack”, a black car pulled up alongside the BMW and a passenger got out and shot Mr Reilly.
The suspect, who was wearing a black balaclava, got back into the car before it sped off in the direction of Maryhill Road. A short time later a black Ford Focus S-Max was found burnt out at Craigieburn Gardens in the Maryhill area. Mr Reilly was taken by ambulance to Glasgow Royal Infirmary, but he passed away on Wednesday.
Detectives believe the attack to be connected to a local feud.
Detective Superintendent Kenny Graham from the force’s Greater Glasgow division said: “Whoever is responsible for this shooting clearly has no regard for the safety of those living in this busy residential area and they must be caught.
“We are continuing our inquiries to establish a motive for this crime and although we believe that this was a targeted attack and that the 29-year-old man was the intended victim, we are pursuing all lines of enquiry.”
He added: “Extensive forensic examinations are ongoing in both Bilsland Drive and Craigieburn Gardens where the burnt-out vehicle was found.”
Chief Inspector Vicky Little said: “We are aware that the local community will be extremely concerned about this incident.
“High-visibility patrols are being carried out in the area and an incident caravan is being set up in the vicinity.
“Members of the public are encouraged to speak to the police about any concerns they may have.”
Anyone with any information or who saw any suspicious activity in the area before the shooting, or witnessed the incident, is asked to call 101.