There are some smaller, lighter cars out there to tow, but as I get older the idea of more protection from the other cars or trucks sounds good. I did think about getting a '73 VW bug to tow behind my '73 MH but was scared everytime I drove one.
Then the airplane thing made a wagon my choice. I looked at some Toyotas and Hondas but they were too much money. So the Subaru found me, and so cheap too.
I never even drove a Subaru before this one, and my planes fit in just fine. The largest plane has a 2 meter wing, thats 78" for us americans. Try that in a VW bug.
So that's my reason to get the Wagon and tow it.