"Gap insurance (guaranteed asset protection insurance) ensures that you don’t end up out of pocket if your car is stolen or damaged so badly that your insurer declares it a 'total loss'
It's designed to bridge the gap between the original amount you paid for your car, and the amount your insurer pays out based on its value at the time of a claim. The actual amount of cover you get will depend on the level you choose when taking out a policy.
Gap insurance can be bought for new or second hand cars up to 10 years old"