I'm kinda curious, do rental rates change for people who own their own car versus people who just have a license? I mean, you definitely have to buy the insurance coverage then, but is that coverage itself more expensive because it's assumed you're not going to be quite as good a driver as someone who does it every day?

Edit: quick google search says some companies might refuse you, but you should be able to pay $15 or so extra per day to get full liability and comprehensive coverage if you have no insurance of your own already. And check your credit card because some of them have limited built-in coverage you can leverage.