Well, the oil drain is way on the other end of the crankcase; I was thinking of a somewhat smaller plate, mostly for the transaxle. Cooling should be a non-issue since that whole thing has its own radiator whose coolant loop runs all the time, and a set of holes through the plate could probably provide sufficient airflow and access to the various fill/drain plugs and electrical connectors. . Research is definitely warranted. I thought of this because I was poking around under my parents' Corolla and their auto trans has a very tidy and fairly close-fitting skid plate mounted under it. And I'm pretty sure their tranny doesn't have a separate cooler.. . _H*
Okay, I took another look under the Corolla. It looks like the "skid plate" is smaller than I thought, and is just an additional bit of metal that's actually spot-welded over the front half of the ATF pan and not actually bolted to anything. So it's nothing like I had in mind for a Prius housing. . Then I crawled back under the prius and looked for solid attachment points, mostly in vain. Mounting points would have to either be all on the transaxle [so it moves with the engine/trans], or all on the frame so the engine moves behind it. And toward the front, the potential points are piteously scarce. But if y'all at BT did come up with a good solution, I'd definitely buy one and evangelize them locally! Having had my share of dirt-bike crankcases saved by such things in the past, I see a real need here. . _H*