Which item is covered under the physical damage coverage of a personal auto policy?

The physical damage coverage of a personal auto policy is designed to protect the insured vehicle against specific types of damage, which includes coverage for sound reproduction equipment that is permanently installed in the vehicle. This type of coverage recognizes that enhancements made to the vehicle, such as an integrated sound system, become part of the vehicle itself and typically are not removed or used outside the vehicle.

In contrast, portable sound systems and sound systems used for business purposes are not considered part of the vehicle and may fall under personal property rather than being specifically covered by the auto policy. Aftermarket modifications may also not be covered unless extra coverage is purchased, as they are often subject to specific endorsements or exclusions outlined in the policy.

Therefore, the correct answer highlights the distinction that permanently installed sound reproduction equipment integrates with the vehicle, making it covered under the physical damage protection offered in a personal auto policy. This reflects the policy's intent to support the insured in maintaining their investment in the vehicle and its components.