The Denethor-dive had my head squeezed between my hands, followed by:
"Oh, good lord." followed by a murmer to my brother: "They're going to have field day with that one on the Downs tomorrow."
I did catch that car in the first movie, but I thought it was only a figment of my imagination when it wasn't in the home versions. I'm glad I'm not
totally insane.
Also, I think that the Gondorians were indeed catapulting bits of the city at the Mordor army. I guess that when the orcs broke pieces off of the walls, they figured they wouldn't waste anything.
Ah, the irony of being crushed by a piece of the city you're trying to invade. Or maybe that's prophetic. Who knows?