Armaguard truck footage captured the moment the grey Audi RS6 - with gun-toting offenders inside - closes in on a cash-in-transit van on Bay Street in Glebe on March 4, 2013.

Two of the balaclava-clad men carrying assault rifles can be seen threatening one of the van's security guards while witnesses to the broad-daylight robbery flee.

One gunman grabs the guard's pistol and fires a shot into the air. Despite their violent efforts, the offenders can't get into the van.

A third man dressed head-to-toe in black clothing is captured running up to the other gunmen and pulling them away from the botched robbery attempt.

From here, detectives believe the stolen luxury getaway car was taken to a garage in the city's inner west and stashed for several months.

Police would not reveal where in the inner west the car was stowed but said it could have been moved around different garages by people close to the criminals.

It emerged the following year and was used in a string of robberies stretching from the western suburbs to the CBD.

Police are now hunting for those people who helped the gunmen involved in the Glebe robbery to hide the getaway car.

"We know the stolen Audi was not seen for several months after the attempted robbery and believe it could have been garaged in the inner west during this time," Robbery and Serious Crime Squad Detective Acting Superintendent Brad Monk said.

"It's also likely the firearms, including the revolver stolen from the security guard, could have been stored in the vehicle for a period of time.

"We are asking the community, particularly residents of apartment complexes in the inner west, to think back – can you recall the Audi being parked in your building's car park around that time?"

Two of the weapons used in the hold-up, an assault rifle and the revolver stolen from the security guard, have never been found.

Detectives believe a considerable degree of planning went into the heist, including casing the movements of the Armaguard truck and establishing the timing of the vehicle's stops.

"It was a very brazen and violent act and the outcome of this offence could have been a lot worse than what it was," Superintendent Monk said.

The grey Audi was found burnt out in Kingsgrove in August 2014 after it was used in a drive-by shooting.

Two of the four alleged robbers, including the getaway driver and one of the gunmen, remain at large.