It would be considered a temporary substitute vehicle on your insurance policy. However, if you don’t have comprehensive and collision on your primary car, you probably don’t on the rental car. Also, if you are using the rental car for business, then it is NOT considered a temporary substitute vehicle on your personal insurance policy. Always check with your insurance agent, as insurance is a state-by-state set of laws, run by each insurance commissioner of that state. So what applies in New York, doesn’t necessarily apply in Florida.