I did the avis preferred thing and it comes with select and go. First question is, since I have to just go to the kiosk and do the check in and payment, can I add liability while I am checking in or I have to go to talk to somebody? In my online account I have the option to add/delete insurance or liability but I decided that I want to have liability and the website says that it takes a couple of days to make the change online. Second question, I did my reservation through costco(much cheaper rates), can I still use the select and go thing?(I put in my wizard number in my reservation and it does show in my account online). Can I still upgrade to a different vehicle class(I know I have to pay extra) ?