In some cases, if a family member is visiting and has permission from the insured to drive the family vehicle, there will be coverage if there is an accident, but the coverage may be limited. All policies should be reviewed to determine if there are any excluded drivers and any limitations on coverage for anyone driving the car that is not specifically named on the policy.
When an insured allows other drivers to drive his vehicle, then, and only then, does the question of whether insurance follows the car or the vehicle become even awkwardly relevant. The right question to be asking is not whether insurance follows the car or the driver, but whether or not other drivers will be covered by the insured’s auto insurance.
In general, insurance coverage for an insured driving someone else’s vehicle is the coverage he carries for his own vehicle. The driver’s personal coverage will apply in most cases when driving a vehicle he does not own. This includes any uninsured motorist coverage he carries and the medical portions of his policy. The driver’s property damage coverage might carry over while driving another’s car as well, depending on the policy language, the respective limits of the two policies involved, and the facts. If a person drives his own vehicle without insurance, he should not expect that he is covered when driving someone else’s vehicle.
Comprehensive car insurance covers damages from an "act of God," or events that are not caused by a car driving into something else. An "act of God" can include things like damage from a heavy tree branch falling on your car. Since you have no control over when or why a tree branch would fall on your car, this kind of accident would be covered under your comprehensive policy.