All that the "undercarraige" protection does is bend up into the
suspension
and drivetrain when you scrape across something. Plastic skidplates are
even
more of a joke, as much as the "Outback" in the real outback:


There are all kinds of off road applications out there and the Outback
is used in plenty. It's one of the top cars around in PA for example
where many homes are set in unpaved areas and outselling all other cars
there and only trailing pickup trucks in sales.
The undercarriage transmission cover is not just for rocks and you
could find almost the same thing on the original and amazing Toyota
Landcruiser.