While you may be covered (read your policy) the deductible per incident will negate any savings on your part.In other words you will be paying for all the smaller stuff including your windshield.
Is there such a coverage that covers everything including other parties involved? I'm struggling to find a hire company that has something plain and simple 'a$$ is covered no matter what happens'.
IF there was that type of coverage it would be priced so high no one would pay for it. Have you taken a good look at all the banged up vehicles??? Imagine a policy that covered all that........... You can't.