The Miniature Travel Trailer Kit by Greenleaf is available for $18.99 at GreenLeafDollhouses.com
A slightly different version of this Vintage Travel Trailer by Corona is available for $19.99 at Miniatures.com
I came across this "Trailer Trash" version by Shamrockgirl18 on Live Journal and had to laugh.
(Top two images from GreenLeafDollhouses.com. Middle two images from Miniatures.com. Bottom three images from Shamrockgirl18's Live Journal.)