For 2-3 people, the labor cost for applying sound insulation cotton is about 1,000 yuan.

1. Open the trunk of the car and take out the spare tire.

2. Cut the sound-absorbing cotton and cover it inside the spare tire cavity. Credit cards can be inserted into the gaps on both sides to restore the trunk storage box.

3. Open the two glove boxes on the left and right sides of the trunk, fold 50*50cm sound-absorbing cotton and stuff it into the gap that can be seen or touched. The rear of the glove box should be flat. Spread a layer.

4. Check other spaces in the trunk of the car and smooth the gaps with sound-absorbing cotton. Installing soundproofing cotton in the trunk can indeed absorb the energy produced by the noise to a certain extent and convert it into energy for dissipation. However, the effect of merely blocking noise through soundproofing cotton is negligible. Since most of the noise is transmitted to the car through the body frame structure, adding sound insulation will not help at all.

Because the sound insulation of the trunk requires disassembly and assembly of the trunk lining, and the trunk lining is mostly fixed through buckles and is easily damaged during disassembly and assembly. If the disassembly skills of the master are not good, it will easily cause problems such as abnormal noise during the subsequent use of the car.