+1 - This is the key.
1. You won't know until you need the insurance. At that point it is too late.
2. Nobody looks carefully at this at the time of the rental because they look very, very carefully if the policy is invoked, e.g. there is an accident.
This is simply a more significantly problematic issue than people who book under discounts to which they are not entitled and ignore the contract provision voiding all coverage if the rental is fraudulent.