Installing sound deadener in your car is a pretty extensive project that can provide you with a number of benefits. However, applying sound deadener in your car can be a very involved project and is not for the feint of heart. It involves taking much of the interior of your car apart, and applying multiple layers of sound deadening material to the body of your car. If you have the patience and are careful when removing and installing your car’s interior, it may be worth the time and effort for a certain level of noise reduction.