The thing to remember is that there's two types of insurance: liability and comprehensive. Liability covers damage you may do to someone else, and often has state mandates. If the state minimum doesn't satisfy you, you can get the ALI (additional liability insurnace).
The actual car is covered by a comprehensive policy, and it's what the CDW/LDW covers. There is no state that requires it by law. Avis may want you to get it because it's very profitable for them, but there's no legal requirement. Be aware that if you have no other insurance at all, you will be repsonsible of the cost of any repairs that are your fault. Damage done by someone else to your car should be covered by their insurance.
If you have a US comprehensive policy, it's almost certain that it covers rental cars too.
With regards to credit cards, even if it's "secondary" coverage, it might serve as primary if you don't have other insurance. (Check the terms.)
I've never been hassled by Avis about insurance -- "Do you want extra coverage?" "No." "Okay, initial here." Same for Hertz and National. Alamo and Enterprise, on the other hand, regularly gave me the hard sell on insurance so I don't rent from them any more.
Last edited by alanh; Oct 28, 2005 at 12:51 am