May I offer some sound advice: Hertz and Avis offer a 'pre-pay' rate that is inclusive of everything. PAI, CDW, PEC, etc.
As a visitor to the country, I think peace of mind is important. Whilst Holiday Autos is nice, the challenge with them is that they sub-buy from different companies. Should anything, Heaven forbid, happen to your car, it's tremendous peace of mind to have companies who literally have locations everywhere. This is often not the case with franchise rental companies such as Thrifty, Econocar, etc. If you choose not to use the prepay feature, use a company like orbitz to look at their matrix which details all the additional fees and hidden fees, such as ...are you under 31 years of age...are you over 65, will there be an extra driver, pre-pay tanks (don't do it!) etc.,
The adage to remember is: The cheapest is not always the least expensive! Bon Voyage Fr. Bill