The practise breaches Auckland Council's public safety and nuisance bylaw which can only be enforced through a prosecution and came into force in May 2014.
"The window washers' behaviour is intimidating and unsafe for motorists, as well as themselves, and they've gone unchecked for too long," Mr Ross said.
Auckland City District Commander Superintendent Richard Chambers said police were aware of the frustration felt by the public and that they frequently feel intimidated by this behaviour.
A change in the bylaw would help give police a greater ability to deal with the issue.
"We would however remind the public that the best way to stop window washing is not to pay them," Mr Chambers said.
Last year, the commanders of the Counties Manukau, Auckland City and Waitemata districts wrote to Auckland Councillor Callum Penrose who chairs the Regulatory and Bylaws Committee expressing their support.
They said window washing, particularly at key intersections in central and south Auckland, had become a significant issue for motorists and was a constant source of complaint.
Mr Penrose said he backed the amendment bill "100 per cent" and that it couldn't be passed quick enough.
The current bylaw meant prosecutions could take months and clogged-up the courts with an infringement which "should be dealt with on the spot with a ticket".
The $150 fine would also act as a deterrent, Mr Penrose said.
"This is a good step in the right direction. [The window washers] are very intimidating. I know some people are happy to pay but if some people don't pay them ... it can get quite scary."
The Automobile Association's senior policy analyst Mark Stockdale agreed with the amendment and said there shouldn't be a demand for windscreen washers because motorists could clean their own windows for free at any service station.
Drivers also shouldn't encourage the activity by paying windscreen washers, he said.
The Auckland City Mission did not respond to the Herald's request for comment by the time of publication.
Windscreen washers prosecuted since May 2014
• Number of prosecutions: 76 individuals, for 135 charges
• Typical penalties: Fines and court costs between $200-$400
• Estimated cost of prosecution to council: $2,500-$5,000
• Duration from charges laid to conviction: 8-12 weeks