Need a car for 2 months

I'm 18 years old and visiting the US for several months, in a suburb with no public transportation, and I need a car to get around. I don't want to buy a car, because I won't be here for that long. And I'm on a pretty low budget. So I'm wondering, what's the best way to get a car for a few months? I've tried the regular rental agencies, but they want to charge me a fortune because I'm 18. I've looked into buying a used car, but for what I can afford ($1500 or so), I doubt I'll be able to get a reliable car. Does anyone have any advice about this?
Thank you.
Ben Buckman