I think of passive aggressive more like the person who has a problem with me but can't tell me directly so then acts all weird about it...So does me avoiding someone's rude advances classify as passive aggressive even when the person is being rude?
You had a problem with her behavior, you didn't tell her directly, and then acted all weird about it. You're posting on a BB about whether or not you were weird or justified.
She thought this was a date. She thought you liked her. You didn't, and she left. You didn't like her forwardness, and so you ignored her.
If a guy asked me out on a ride, I would assume there were romantic feelings there and might act accordingly. I don't think this is some crazy jump to foregone conclusions. It just sounds like a date.
I appreciate that she came on too hard too soon for your taste, but I encourage you to own what's yours here: You decided -- after inviting her into your friend circle -- that acting with emotional distance/passive aggression was preferable to saying what you felt. She got your point, sure, but now you have the yucky feelings that go along with all the awkwardness of poor communication.
Remember, YOU invited HER. You don't owe her sex, a date, a drink, a ride, or an explanation, but the decency of stating your intentions as soon as confusion was present would have been good. It's the decent and ethical thing to do.
If she reacted poorly to your clarification, that's on her. But you didn't give her the chance.