Just sold a car, got a couple of questions...

[Naim]

I just sold a car (Audi S4)...
People came from Indiana (I'm in Milwaukee Wi)...
They put $500 down and are going to give me a cashiers check for the rest.
I am going to drive down to Chicago meeting them half way, where they will give me the cahsiers check and I will give them the car and title.

What is a good way to make sure that a cashiers check is good (not fake)???
It's not that I don't trust the people, it's just that I want to cover my butt.

Thanks.