CAP cover (leasing vehicle) and hedging in case of total damage caused by external debt

Moin! Quick question about leasing insurance. My father-in-law in-law can pick up his new Audi A5 convertible (almost – 2 years duration) from the dealer at the beginning of next week. Today we wanted to conclude an insurance with CAP cover (difference of new and current value of the vehicle is covered in case of total damage or theft). I came up with the following question, which I have not yet received from any of the three insurance companies where I called and which have received such a CAP What is the problem of accidents that lead to total damage? All customer hotlines agreed that the CAP coverage of their own insurance does not apply, since the accident was not caused by a self-indebted person. Different statements were made as to whether the opposing insurance only had the time value of the vehicle, or the “actual, economic damage” (i.e. in the worst case the Neuwe rt, which the lessor requires from the lessee), and whether it is necessary to claim the difference in the cause of the accident itself. Has one of you by chance already gained experience and can answer this question to me? Thanks for the post! Greetings