Police say illegal car modification needs to stop, following the sentencing of a teenage driver who killed a four-year-old Christchurch boy.
Ashley Austin, 18, was sentenced to six months community detention and banned from driving for three years after he admitted dangerous driving causing the death of Nayan Woods.
Nayan Woods was walking home with his mother and older brother along Linwood Ave in May when Austin's car mounted the footpath and crashed into him.
Austin admitted driving a modified car which the police say was unfit to be driven on a public road.
Constable Graham Flynn, who was at Wednesday's sentencing, says it's all too easy for people to get parts to illegally modify their cars.
Ian Stronach from the Motor Trade Association says some modifications are comparatively easy to do and don't even need special parts. He says more thorough roadside enforcement is required.
A group advocating reduced noise levels in modified cars says a law change stipulating quieter exhaust systems could prevent deaths.
Jonathan Gillard from Noise Off says lowering the permissible noise level of modified exhausts systems from 95 to 90 decibels could stop boy-racers from driving dangerously.
Mr Gillard says boy-racers show off the noise from their modified exhausts by speeding. He says 95 decibels is five times louder than 90 decibels, which is the maximum noise level allowed from the tail pipes of cars in Australia.