With both collision and comprehensive, insurers will usually only cover the Actual Cash Value (ACV) of the cost of the car. ACV is determined by taking the replacement cost of the vehicle—what it would cost to repair damage to the vehicle without deducting for depreciation—and subtracting the depreciation. So, if a car is bought for $10,000, and is 10 years old, the ACV of the car would be substantially less than $10,000.
Drivers willing to pay a higher premium can get insurance policies that will cover the replacement costs of the car. Depending on the age and condition of the vehicle, these kinds of policies may be worth it, although they are usually not recommended for older vehicles.