Claiming insurance for a rented/loaned car

I rented out a car through an informal arrangement: The technical workaround used was to classify the car as being "on loan," while the payment was defined as compensation for wear and tear. This was done in order to avoid halachic complications related to insurance policies, which typically do not cover rented cars but do cover loaned ones.However, the car sustained damage which was beyond anyone's control (באונס) My questions are as follows:Is it permissible according to halacha to rent a car in this manner?If not, what is the halachically permissible way to rent a car?In this case, where the damage that occurred was beyond anyone's control (באונס). The renter claims it was a rental, and therefore he is exempt from liability for accidental damage. I, on the other hand, claim it was a loan, in which case he would be liable. What is the halacha in this situation?

Shalom, 

1. It is forbidden to rent or lease a car in a way that deceives the insurance, this is considered theft. 

2. You must approve the additional driver with the insurance company according to their rules. 

3. After all, you yourself say it was for payment, and therefore it is considered as a rental and not a loan, and therefore the renter is exempt from paying for the accidents that was beyond anyone's control (באונס).