Anyone who drives my car covered under my auto insurance policy?
Yes, in most cases the person driving the car is covered provided they have permission from you or he is listed in your insurance policy. One exception to this general rule is the person uses your car regularly but is not listed.
The assumption is persons who borrow your car do on rarely and those that do borrow regularly are listed. Anyone outside of this premise is assumed to be a high risk driver which is why you won’t list that person in your policy. If you do, it would cause your premium to increase.
Thus, a person living with you should be listed and a person not living with you can be considered an exception.
Go over your insurance policy and look for “Permissive Users.” The policy should explain the company’s position on non-listed drivers and the liability limits, if any. You should also check if the liability limits are reduced with permissive users.