Tonight I did a search for 1967 vintage trailer advertisements. Just like that - no quote marks.
Oh my. This turns out to have nothing to do with travel trailers (or trailer parks).
Indeed, it appears to be a very strong moral lesson aimed particularly at young ladies of a certain age. Watch the amusing and somewhat disturbing movie TRAILER...
AND LET THAT BE A LESSON TO YOU!
I was really looking for something more along these lines... honest!