Posted by Ronan Kelly Services

What are illegal modifcation to cars?

Modified cars – what you need to know

Cars can be modified to improve performance or style. If you’re considering modifying your car or you have purchased a modified car, you can find information below on modifications including in-car entertainment, lights or reflectors, suspension and brakes.

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Safety first

Staying safe and legal is extremely important when modifying your car. It is essential to remember that too many modifications can affect the road handling of your car. It could also put you on the wrong side of the law and perhaps your insurance company.

In-car entertainment

Over the last few years there has been a huge increase in the amount of in-car entertainment devices that have become available for the motorist.

However, it’s important to remember that as technology improves, the driver of the car still has the most important job to do – and that means they must not get distracted by in-car entertainment, such as watching a TV screen in the rear-view mirror, or rummaging around with an MP3 player. Moving images within view of the driver are illegal whilst driving.

Lights or reflectors

Headlamps must show a substantially white or yellow light. Rear position lamps must show a steady red light to the rear only. Tinting of rear reflectors which will reduce efficiency in darkness is not permitted

Wheels and tyres

Changes to wheels and tyres can significantly alter your car’s behaviour on the road. Important points to consider when fitting bigger wheels and tyres is to:

  • ensure they are approved by the vehicle manufacturer
  • provide adequate clearance between tyre and bodywork


Modifications to the suspension which is the fitment of stiffer springs and lowering kits, should be only be done where the car’s road handling will not be compromised. This work must be carried out by a competent engineer.


Modifications to your car’s brakes must at all times be carried out by a competent engineer. Before parting with your money, seek advice from independent suppliers and the vehicle manufacturer to ensure that the brakes you intend fitting are approved and will not involve any major modification of existing mounting points.

Number plates

Number plates must:

  • comply with current legislation
  • be displayed in a prominent position
  • not be misleading

Exhaust system

All exhaust silencers must be maintained in a good and efficient working order. You will be breaking the law if you remove a silencer or make any modification that would make that vehicle emit a noise louder than the original exhaust before it was modified.



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