Is it illegal to modify the carbon fiber hood?

According to relevant regulations: Before a licensed car is modified, it should be registered and reported to the vehicle management office. The modification technical report can only be modified after being reviewed and approved by the vehicle management office. After the modification is completed, you must go to the vehicle management office to handle the modification change procedures. If the above procedures are completed, it is not illegal.
For some car friends who are keen on modification, I have sorted out the following items that are allowed to be modified in the following countries:
1. Appearance modification
You can apply to the vehicle management office for modification of the body color. For body film, my country stipulates that the area of ​​body film shall not exceed 30% of the area of ​​the whole vehicle. Some small decorations and body decals can still be pasted.
2. Replacement of engine/frame
The engine, body, and frame can only be replaced with the original model, and a repair shop certificate and origin certificate must be issued, and the vehicle information must be registered at the vehicle management office to apply for changes. Modification of single exhaust pipe to dual exhaust pipe; modification of exhaust pipe to large-caliber and loud exhaust pipe, etc., are all illegal modifications.
3. Luggage rack/pedal
SUV will look more off-road if these two accessories are added. Some models on the market are already standard. You will not be caught if you add these two accessories, but they need to be removed during the annual inspection.
4. Car interior modification
In terms of interior decoration, in principle, it can be modified without affecting safe driving. However, the seats cannot be removed, the interior structure cannot be changed, and the structural characteristics of the vehicle registered with the vehicle management office cannot be changed without authorization. The navigation, driving recorder, reversing radar, etc. installed by the owner later are all considered modifications, and these are all fine.
5. Full car sound insulation
Many car owners plan to do it, but the internal decorative panels may make abnormal noises due to assembly problems. Please do it within your ability.
6. Add speakers
Those who pursue music hope to modify it. Because it involves wiring problems, it must be modified in a formal place.