Modified Vehicles

The NCT now includes additional test items for vehicle modifications such as exhaust noise levels and window tinting.

Vehicles can be modified for various reasons - some vehicles are modified even before they are registered. For example, someone can convert a four-wheel drive passenger vehicle into a commercial vehicle by removing the back seats and safety belts. Work on a vehicle which affects the safety and/or handling of a vehicle e.g. brakes, steering, suspension etc. must be to a minimum standard and comply with the law.

Other modifications are cosmetic – to personalise a car and make it different to others of its type. Common ones include rear spoilers and side trim, adapted exhausts and tinted windows.

Section 62 of the NCT Manual 2014 (PDF) deals with vehicle modifications .  This provides more guidance on the modifications which require a modifications report. The format of the modifications report is available here.

For more information on vehicle modifications, please see our Registration and Motor Tax webpage or alternatively the vehicle conversion section of Revenue Commissioner’s website or the Motor Tax RF111 Change of Particulars Form (PDF).

Window Tinting

Excessively tinted windscreens or front side windows present a significant safety hazard for vehicle drivers and their occupants.  Visibility is greatly reduced, particularly for night time driving and at times of low light.  There are also enforcement issues for An Garda Síochána in regard to driver recognition, the detection of driving offences e.g. holding a mobile phone while driving, and other criminal activity.

If the NCT vehicle inspector deems that the windscreen or front side windows are excessively tinted the level of light transmission of the window will be tested.  The glass in the windscreen and front side windows will be required to have a light transmission level of not less than 65% in order to pass the NCT test.   Tinting of these windows must not be greater than 35%.Unfortunately the National Car Testing Regulations do not allow for any exemptions in this regard.

Tint films tend to be quite easily removed and replaceable with a compliant film which would block UVA light and meet the requirement of not less than 65% light transmission.  There is no limit on the tint level in the rear window and rear side windows.  

Vehicle Exhaust Noise

Vehicles are required to have a level of noise no greater than 99dB(A) in order to pass the test to ensure that vehicles comply with acceptable noise levels. An Garda Síochána currently use sound measurement equipment at roadside enforcement checkpoints throughout the country. The penalty on conviction is a fine which, depending if there have been previous similar convictions, may not exceed €2,000 and/or, at the discretion of the court, imprisonment for a term not exceeding three months.

Enforcement of Road Traffic legislation is a matter for An Garda Síochána.

Customers should also ensure that their vehicle registration documents match the vehicle as this will be checked against the vehicle file.