I stumbled across this great little article in the archives of QST. It's titled "Antennas for Travel Trailers and Campers" QST March 1969 by Philip S. Rand (W1DBM
now a SK).
The best part was the author was an Airstreamer! He belonged to the New England Unit. The first paragraph made an interesting point. He cited the average number of ham's per population was 1:1000, but within the WBCCI (at that time) it was more like 10x that number!
The article goes on to describe some novel antenna configurations that he used on his Airstream, including a dipole that stretched from the front to the back 30' from masts on the jack post and the bumper. There are great pics of his Airstream and all of it's antennas.
The link to the article is here
. Scroll down to the title above and right-click to download the pdf.
Unfortunately, it is a member's only access from the ARRL.