Your friend drives your car and causes an accident with a lot of damage.

Let's say the accident your friend causes results in serious bodily injury to others and property damage. Liability coverage consists of two parts: bodily injury liability and physical damage liability. The driver's policy covers the driver and all passengers in the vehicle for bodily injury. The car owner's liability covers property damage caused by his or her car. Liability insurance also covers the cost of your legal fees in the event that you are sued.

But if the damage exceeds your insurance liability limits, the courts can attach your personal assets, such as your home, to recover damages. Liability coverage won't pay for damages beyond the limit for which you are insured.

Cases in which you and your friend share the cost of the accident are known as "pro rata." If your friend was at fault, your insurance companies can share the cost. For example, say your friend causes $11,000 in property damage while driving your car. You have $25,000 in property damage coverage and your friend has $15,000; total coverage is $40,000. You and your friend may share the cost proportionally. Initially, your insurance would likely pay the full cost of the accident. It would then seek compensation from your friend's insurer to recover his or her share.