The killers of former bikie boss Mahmoud "Mick" Hawi have been warned police are closing in after investigators seized four cars connected to his execution.
"At the moment we would say there would be a number of people feeling very uncomfortable, and we would like them to feel uncomfortable," Detective Superintendent Deb Wallace said on Thursday.
Strike force investigators swooped on six properties in Sydney's south on Thursday morning and seized four cars believed to have been used in planning the brazen daylight shooting of the former Comancheros president outside a Sydney gym in February.
Investigators in March seized a stolen silver Toyota Aurion believed to be one of two getaway cars.
Forensic evidence found in the car made Thursday's raids possible, police say.
A total of six cars - including a burnt out Mercedes found near the crime scene a few hours after the attack - have now been seized.
"This was well coordinated and well planned ... a number of vehicles were used in the movement around that time of the murder," Det Sup Wallace said.
Investigators say the Aurion was driving near the Fitness First gym in Rockdale on the morning of the murder in convoy with a black Toyota Prado.
After the shooting it's believed the attackers fled on foot before getting in the Mercedes - it was later abandoned and set on fire. They then jumped in the Aurion and fled the area.
The Aurion was seen two days later on a tow truck in Botany and was seized by police in Beaconsfield in March.
The seizure of the cars makes up "important pieces of the jigsaw puzzle," Det Supt Wallace said.
"We believe this involves a number of people involved in the planning, the facilitation, the execution - so we're closing the net."
Along with the cars impounded on Thursday - which police say weren't stolen - authorities seized $22,000 in cash, mobile phones, documents and a radio capable of monitoring police activity.
The properties targeted had no specific links to the Comancheros motorcycle club which Hawi once led, NSW Police said.
Footage of the shooting aired in March shows the 37-year-old getting into his four-wheel drive parked outside Fitness First before a gunman - dressed in black - runs towards the driver's side of the car.
The gunman - at arm's length from the car - appears to fire multiple shots at Hawi in the driver's seat.
The attacker then leans into the car and continues firing before running from the carpark. Hawi died a few hours later in St George Hospital.
His luxury 4WD was peppered with at least half a dozen bullets.
Hawi, himself a convicted killer, was imprisoned over the 2009 bashing death of Hell's Angels associate Anthony Zervas in a wild brawl at Sydney Airport.
He was released in 2015 and mainly flew under the radar until he was murdered.