I took advantage of a girl at the rock concert
How did you take advantage of her?
I forced her to come with me to the parking lot where I ended up fucking her.
You "made her" against her will? It's wrong on so many levels to force anyone to have have sex. If you have a compulsion to act this way, you should seek help.
How did I make her against her will. She came with me to the parking lot because she wanted to have sex with me.
Well if she wanted to go with you and have sex then you are fine. Just be sure that you are not forcing anyone to have sex with you as this is very wrong.