> .........
>  where
> does the grey water go? On my parts van the drain is just sticking out
> the bottom, which I doubt most campgrounds would be too happy about.

Yes, that is the correct location.  It has a threaded end that you
can connect a garden hose to & run to a remote location or sewer if
in a campground that has a sewer near where you are parked.

> Is there supposed to bea holding tank below?

Option by current owner!  There are many different versions of this,
including letting it run on the ground, a pan or bucket, or actual
greywater tanks installed by the owner.  YMMV.

Tom B.-use a hose only used for this reason or a plastic dishpan
depending on where I am camping, type of greywater.

>
> Nathaniel