He then went to stand in front of the police patrol car before raising the canister above his head and threatening "I'll do it".
Keil's actions resulted in the front windscreen shattering and a dent in the bonnet.
He was arrested at the scene.
Today he pleaded guilty to wilful damage and driving while prohibited.
He appeared in front of Judge Tony Adeane who convicted and discharged him on the basis he could pay $2280 in reparation, the cost to repair the police car.
Keil told Judge Adeane he was starting a job next week and would be able to pay the $50 a week reparation sought by police.
He then reappeared before the court to advise Judge Adeane he did not in fact have a job lined up and needed to contact his father about setting up the reparation payment.
Judge Adeane said he had misinformed the court and sentenced him to seven days' imprisonment.
The judge advised him he would have access to a phone in prison so that he could sort out his employment situation and said the original sentence had only been imposed on the misinformation provided by Keil.
He asked Keil if today was going to be a day where they "play games" with each other and informed him he would be spending a lot longer in jail if he could not sort out a way to pay reparation.