Most basic auto insurance policies will insure a driver and his vehicle for bodily injury and property damage. The specifics of this coverage and the amount paid out in the event of a claim differ from policy to policy, but most basic policies cover those two things.Some drivers want additional coverage, however, and take out supplemental auto insurance to ensure they are covered for more than just the basics. Adding these supplemental items onto a policy will often increase the insurance premiums, but they can be well worth it in the event of an accident.Some of the most common types of supplemental coverages offered by most auto insurance companies include the following:Uninsured/Underinsured: This is coverage for when a driver gets into an accident with a driver who does not have adequate insurance to cover his responsibilities. It also covers a driver in the event of a hit and run. Some states require uninsured/underinsured coverage, and in those states it is not considered supplemental insurance. However, in states that do not require it, it is considered supplemental.Emergency Roadside Assistance: This is a basic type of roadside assistance that will bring a tow truck in the event of a break down, give a jump to a dead battery, or help in the event of an accidental lock out.Rental Reimbursement: If a vehicle needs to be repaired because of an accident, this type of supplemental auto insurance will cover the rental of a temporary car.Mechanical Breakdown Insurance: This insurance covers a vehicle in the event that there is a mechanical failure, not an accident.Other types of supplemental insurance that are not as common, but are offered by many companies include:Gap Insurance: If a vehicle is totaled, and the amount that the insurance company pays out for the vehicle is less than what the owner owes on the vehicle, gap insurance covers the difference.Pet Injury Coverage: This is fairly self-explanatory. A pet involved in the auto accident is covered for its injuries.AutoCarInsurance.org provides you with multiple free quotes on these supplemental insurance coverages. Begin by entering your zip code in the box above.