*wonders if Remdul has forgotten that he worked on TC_Isle
or maybe he just wasn't involved too much after the models were done* Weelll in TC_Isle, the physics of the crater door are quite real all the time it's moving slowly into the wall. What it is is that it will go to its directed location by the ASA file, regardless of what's in its path. It will still push things out of the way, and will not give way itself, as if it has near infinite mass/density and doesn't suck you in like a black hole.
Also the player is animated through the water by an ASA animation at the very end of TC_Isle, which is rather fun to see. I'm pretty sure the camera even rolls as a result (not something that happens often in games).
The thing you have to be careful with when you stick Anne/whoever in a truck is that the physics will have to keep her blocked up; Trespasser interprits no "gripping" friction, or attached masses (except by the class of trigger of course), so if the object under Anne moves in a direction, she will remain still and it will move out from under her. The baloon seems to have been designed with this in mind, the walls of the um.. hanging thing are all that keep you moving with the baloon.
It could work for a car, you would need very dependable terrain and a way to very accurately export it, which is not really possible with JPDS for example (large, non-retail terrain). That doesn't matter cause I don't plan to do it in JPDS.
About firing from the car as it rides along... well... stay tuned
for a while... LOL