My wife's 2004 DII (~110k) has had disappearing coolant for a couple weeks. The cause turned out to be was a blown hose from the manifold to plenum de-icer. I replaced the hose and basically it blew up like old faithful right under the throttle body gasket. I've replaced that before, but never seen a leak with this much pressure when the engine is off.

I'm thinking a new throttle body gasket, but wanted to check and see if there is anything else I should look at while I'm in there. All hose connections are solid.