I have two estimates for car hire. I have been promised they (Avis/Hertz) will not charge nor hold any amounts of money for declining CDW insurance. So...is it the local desk at the airport that will want to charge or put a sizeable hold on my credit card?
I would get it in writing from the company. If they try to charge you at the airport get out your written reply and show it to them. Because they will try to sneak anything onto the contract that they can.