Aman Trivedi
It is the easiest way to reduce the unwanted noise in your car and also a great option for the general acoustics of the car.
Put small foam pieces around any moving part making a rattling noise, like the rear parcel shelf to reduce or eliminate the noise.
These loose things can create a lot of noise in your car, you can either remove them or tie them properly to get relief from noise.
If your car doesn't have this, then aftermarket insulation can work great to reduce noise in the car caused by road debris hitting the bare metal.
Worn-out tires can make a lot of noise on roads, so it's a great idea to opt for new tires to improve the car's strength and reduce unwanted noise.