Ponga then grabbed a golf club and chased the car, smashing two windows, including the one above the baby, Judge Cameron said.
"The defendant claims not to have known that children were inside the car."
Ponga pleaded guilty to assault with intent to injure and wilful damage. He also pleaded guilty to two unrelated charges of breaching a protection order.
The first arose from an incident on December 3, when Ponga was arguing with his off and on partner of 10 years.
"The defendant went outside and started screaming and yelling abuse," Judge Cameron said.
He went to another door and tried to get back inside the house, and began kicking it when he couldn't.
On December 20, an argument started between the pair when the victim accused Ponga of smoking P.
Ponga verbally abused the victim before picking up her keys and taking a key to her workplace off the key ring.
He refused to leave the house, although the victim told him to "numerous times".
Judge Cameron said Ponga had an "extensive" criminal history. He sentenced Ponga to six months in prison with six months of post-release conditions, and ordered him to pay reparation of $500 to the first victim.