Been there, done that. Though I don't recommend doing that in real life. It turns out that people actually get really really pissed off when you comment on their weekly 50 - 60 dollar gas receipt. Some doofus was sitting at a red light near me and my carpooler revving their engine. We sat there silently and I told my passenger that I was revving my battery. We got a bigger chuckle out of that than anything else.
