What motor? 3.8 or 4.0?
Unfortunately, the problems you listed that you had with the van have noting to do with oil consumption, so I don't think throwing that around at the dealer will get you too far. Ultimately you are responsible for checking the oil, BUT, when you had it in for the 36K oil change, don't you think they should have told you that the van was low on oil? I mean, even though I would be just about ready to do an oil change, I always check the level just before draining it. Force of habit for me, but for a tech they probably just pop it in the air, pull the plug, go get a coffee while it's draining and never actually see how much came out. Perhaps you could look into the power train warranty for the 09's, maybe it is 50K, but it's gonna be hard to make that stick since there was no oil in it. Only plus side is, if you mechanically inclined, the Dodge and Chryslers are like a-holes, everyone has got one so there should be plenty of them in the boneyards to get a motor from. Sorry man, keep us posted.