Now that I think about it a bit, attaching a base for a trunk via the hitch won't work cuz the trunk will block out the turnsignals and tail lights, unless I raise it up a bit. On the other hand I could rig up additional plug in signals and tailight on top of the trunk.
I don't want the hassle and limited parking options of a trailer.....or the expense. However, two up on a long trip and a trailer seems near mandatory especially if you are camping.