I disagree. Check with your credit card company. I rented a car in France several years ago, and some thieves smashed the drivers side window. It cost me $92 to get new glass put in, and VISA reimbursed me, when I got back to the USA. I had to fill out a form, and provide them with photos of the damage, a copy of the police report, and the repair bill.

I had nothing in the car, except maps - which were not stolen. I see no need to pay extra for coverage which is provided for free by your credit card company.