The gunmen who killed Malcolm McKeown in County Down last month waited at the filling station for nearly an hour, police have said.
In newly-released CCTV footage, a dark blue VW Passat car is seen driving into Dewart’s service station in Waringstown at 18:23 BST on 19 August.
The car left the filling station 56 minutes later.
The 54-year-old was found dead in his silver BMW behind Dewart’s shortly before 21:00 BST.
Mr McKeown had been shot six times.
The VW Passat was later discovered burnt out on Glenavon Lane in Lurgan.
Det Ch Insp Peter Montgomery has asked for witnesses to come forward.
“There was football training and trials ongoing nearby so there may be some parents who witnessed the Passat on fire,” he said.
“This was a chilling murder carried out at close range in broad daylight. Mr McKeown was the father of three children and his family deserve to see justice done.”
He also repeated an earlier appeal for information on another car, a grey VW Golf, that was seen in the Greenhill Park area on the day of the murder.
Police believe the murder is connected to a “long-standing feud”.