Feithiclí athraithe

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 such as this must be to a minimum 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.

The Safety of modifications

If a modification effects the safety of a vehicle, the owner must present an engineers report at the roadworthiness test to show that the modification complies with the law and that they completed the modification to a high standard. If the modification changes the registration class, the vehicle must be re-registered.

The RSA has no difficulty with modifications so long as they don’t impair the safety of a vehicle, comply with the law and are not a nuisance to the public. To reflect the fact that some modifications can have wider negative impacts, we've added two additional tests to the NCT.

NCT changes (from 1 April 2010)

The new items are as follows:

Clarity of windscreen and front side windows

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 test.

Rear fog lamp

The rear fog lamp, where fitted, will be checked to ensure that when in use it provides a red light which is clearly visible.

Reverse lamp

The reverse lamp, where fitted, will be checked to ensure that when in use it provides a white light which is clearly visible


A vehicle will fail if an “E” or “e” mark is not visible to ensure that the tyres comply with minimum standards.

Indicators warning of faulty systems for Airbags, Electronic Stability Control (ESC) and Electronic Braking Systems (EBS) / Anti-Lock Brake Systems (ABS)

The vehicle will fail if a faulty systems indicator is not working or indicates a fault in the system.

Rear registration plate lamp

If the rear registration number plate lamp(s) is not working properly, a Fail Advisory will issue i.e. it is strongly recommended that the fault be repaired, but, the vehicle will still pass the test.

Vehicle exhaust noise

The vehicle will be 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.
Please note that customers are now required to produce a valid driver’s licence or passport when presenting a vehicle to NCT.


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