If she likes you then you should talk to her cause if your shy then she is probably more shy then you and forget about your friends cause if it ends up working out then your friends will think of you as a god and if it doesn't then they should still think that it was cool you had balls to do it. I might be wrong but a think you should just go for it otherwise you will never know!! Maybe you could write her a note, asking to meet someplace at a specific time. Then just fold the note and put it in her hand next time you're getting out of the carpool.