This month, the ministry released amendments to its Land Transport Rule Vehicle Equipment (Noise) Amendment 2009 for public consultation.
Under the proposed changes, vehicles with exhausts louder than 95 decibels would have to be altered to meet a lower 90 decibel limit.
The use of externally vented or un-muffled types of "blow-off valves" on turbocharged vehicles could be prohibited.
Inspectors testing vehicles for a warrant and certificate of fitness could send light vehicles for a metered tail-pipe noise test if the exhaust was considered to be louder than the original system.
Inspectors would not have to give vehicle owners the option of repairing the exhaust first.
Police would have the power to send for testing a vehicle with an overly noisy modified exhaust.
Transport Safety Minister Harry Duynhoven told the Otago Daily Times the Government had been aware of the need for the past two years to "gradually tighten the noose" on noisy cars.
"We have been making changes and now want to target those who are a nuisance, instead of making every motorist have a noise test.
Over the years, we have imported vehicles with modified big bore exhausts and have been forced to accept overseas standards for these.
I would now estimate we have between 50,000 and 80,000 vehicles with exhaust systems which may be above 90 decibel but below 95 [decibels] on the roads."
Mr Duynhoven said the "street light grand prix" scenario in cities such as Christchurch prompted the ministry to consult the public on further changes to legislation introduced in June.
Compulsory ratings of 90 decibels or lower would apply only to vehicles manufactured after January 1, 1985, and exemptions would apply to older vehicles.
"Classic vehicles are not necessarily on the road at 3am doing 8000rpm, so were not included. The 'blow-off' valves were seen as an issue as they are there to create a noise effect and make a complete and unnecessary racket."
Southern district road policing manager Inspector Andrew Burns, of Dunedin, said police in the Southern District issued 447 notices for noisy vehicles between July 2006 and June 30, 2007.
Between June 30 and July 2008, 476 notices issued.
"These figures indicate there is a significant level of offending. We would probably get as many complaints about noisy vehicles as we would about speeding.
"We recognise the annoyance factor is significant for those sitting at home, particularly when 'blow-off' valves are heard in built up areas.
"But we are looking forward to the changes as another tool which could free us up to look at unsafe driving and speeding more."
Vehicle Inspection New Zealand compliance certifier John Murdoch, of Dunedin, said the the centre had this month bought a sound meter to measure the exhaust level of imported vehicles and those undergoing warrant of fitness checks.
He had noted a slight decrease in the number of modified exhaust systems on vehicles presented for testing.
"There's certainly no more than there used to be. In fact, a lot of guys are going back to the standard system on certain vehicles," Mr Murdoch said.
Imported vehicles with modified exhausts which failed a subjective noise test would need to be repaired or take a metered test and meet the 90 decibels maximum noise level.
In June, penalties for operating a vehicle in a noisy manner were revised and now carry a 25 demerit point penalty for motorists and a $50 fine.
Submissions on amendments to vehicle noise legislation close on September 17.
