Response : This is a very intersting question and a much debated issue even in our insurance world. The comparison of car rental insurance for physical damage is interesting, however I would like to talk about the present version of this coverage. Let is compare auto insurance coverage on rental car.
As per the prevaling car insurance regulations, if you have physical damage coverage or PAP coverage on one auto than when you rent a car it would cover the physical damages but you will have to pay the deductible amount on this which is as per your PAP – auto insurance policy. Presently the coverage for nonowned cars moved back to physical damage (where it still is today), thus requiring PAP insureds to carry such coverage on at least one car and to pay their own deductible in order to have physical damage coverage for a nonowned car. The insurance company is not happy with this since their exposure has doubled. They are liable for the car you own and also the non-owned car you drive. The rental companies no longer carry physical damage on their fleets, the PAP insurer is now responsible for the difference between the insured’s deductible and the amount of damage to the rental car—up to the value of the car.
In 1989, an exclusion regarding damage to rented cars was added to the PAP. That exclusion removes coverage (including coverage for loss of use) if the rental company is not allowed by state law or the rental agreement to collect for a loss. Under previous editions of the PAP, the rental company could collect under the named insured’s PAP even if the insured was not legally responsible for the loss, such as in the case of hail damage to the rented car. This exclusion was added to prevent the rental company from collecting under the named insured’s PAP in such situations.
The golden nugget for you here is that you should compare auto insurance coverage and see that you are covered under your auto insurance policy for the physical damage and this will follow you when you drive a rental car. So review car insurance coverage and as long as you have all the coverages, do not worry.

Happy holidays.

Thanks.
Kamlesh