新西兰租车，保险费，信用卡的问题

新西兰租车，租车公司给的回复:

“Our standard daily insurance has an excess ( deductible ) of $NZ2000.
Additional insurance is available ( optional ) which will lower the excess.
To lower the excess to $NZ500 there is a charge of $NZ12.00 per day
To lower the excess to $NZ250 there is a charge of $NZ16.10 per day

Here is a tip for you.
It may pay to check with your travel insurance and/or credit card company.
We are now finding that about half the travel insurance companies and some
credit card companies now cover rental car excess for free.
Worth checking”

请教国内visa和master客户，信用卡是否覆盖的？

另外，是否需要加上addtional insurance?