A twenty doesn't buy what it used to, but some rare 20-dollar bills can actually be worth a lot. Knowing what to look for can help you spot a bill that's special (and could be worth more than your car ...

Add Yahoo as a preferred source to see more of our stories on Google. Ashley Taylor Ayers via Shutterstock A twenty doesn't buy what it used to, but some rare 20-dollar bills can actually be worth a ...