The legality of car modifications varies by country and region. Here are some countries and regions' legal scope for car modifications:

1. Singapore:
Vehicle modifications must comply with international automotive standards and technical requirements. Modifications are divided into three categories: modifications that do not require approval from the Land Transport Authority (LTA), modifications that require approval, and modifications that are not permitted. Any unauthorized modifications may result in a fine of up to S$5,000, 3 months in jail, or both. In addition, car owners should notify their insurance company after modifying their vehicles to avoid having their claims rejected or their insurance policies voided in the event of an accident.
2. United States:
The laws on vehicle modifications vary from state to state. Some modifications may not be obvious, such as window film, while other modifications such as loud exhaust systems or custom lighting may be easily spotted. Car owners should understand the laws in their state before modifying to ensure that the modifications are legal and avoid being ticketed or fined by the police. California is known for its strict car modification laws, which are regulated by the California Air Resources Board (CARB) and strictly control the approval of "aftermarket" parts.
3. India:
Under the Motor Vehicles Act, 1988, owners are not allowed to alter their vehicles so that the contents of the registration certificate are different from those originally specified by the manufacturer. However, if the modification is for the purpose of improving fuel efficiency, reducing vehicle pollution or other special purposes exempted by the central government, and the modification is approved by the state government, it can be carried out. The Supreme Court's ruling is not a blanket ban on all modifications, but restricts those modifications that may affect road safety or increase pollution.
4. UAE:
Car owners must obtain certification and approval from official checkpoints when modifying their vehicles. Modified vehicles need to pass the review of special inspection centers to ensure that the modifications do not constitute a road hazard. If the modification violates the rules, there may be fines, vehicle seizure and even imprisonment. In addition, modifications may also affect vehicle insurance, and car owners should notify the insurance company to keep the insurance valid.
5. China:
As more and more Chinese people own cars, car customization and modification have become more popular. The Chinese government encourages customer to manufacturer (C2M) production and implements guidance to optimize the management of the car modification market. Customers can now customize their vehicles when placing orders or modify them at authorized modification shops to ensure compliance. The Chinese modification market is valued at $10 billion in 2021 and is expected to reach $31.2 billion by 2025. In China, modifications such as changing the color of the vehicle, replacing the engine, and changing the body or frame of the vehicle require the owner to apply for a "change of registration".
When modifying their car, car owners should always comply with local laws to ensure safety and avoid legal problems.
