Gary Bulmer, 75, a grandfather of 15, described the encounter.
“He said, ‘open the door, open the door’,” he said.
“I said, ‘p— off’, because I thought it was one of those toy guns, and it wasn’t, it was one of those home-made things by the look of it.”
Bulmer said the man was “shaking” during the threats.
“The offender drove off in the Holden Commodore and police were notified,” Victoria Police said in a statement.
Bulmer gave up his Holden Commodore but not without a fight.
“I said, ‘okay a——-, it’s yours,” he said.
Bulmer’s car was found half an hour later, when detectives rammed into the alleged carjacker.
Gunfire then broke out along Warrawee Avenue.
“Officers approached and were confronted by a man with a firearm who was subsequently shot by police,” officers said.
The alleged carjacker is in hospital in a stable condition.