General insurance companies offer a range of optional add-ons that give additional cover to your car along with the base motor insurance policy. While add-ons like zero depreciation, engine protection and return to invoice are some of the very common and prominent add-ons that most car owners chose, there are some lesser-known add-ons as well that are as important and beneficial as others. It is significant to look under the hood of each of these additional covers to understand what they offer and how they work.