Wheel Estate (Johns Hopkins Press, 1997) is an in-depth look at mobile homes and housing. It was originally published in hardcover by Oxford University Press in 1991, and it's dated, but full of historical background and photos.
I bought it when I discovered that my uncles, who were pioneers in the mobile home field (they began building them on my grandparents's farm, where I was born), are mentioned in it. (They would really gnash their teeth when people called mobile homes trailers. I was raised knowing the difference.)
For a while my family lived next to the first factory (Rollohome) and I'd visit it sometimes.