The best of the latter, I think, is After Things Fell Apart, which was published in 1970 and set a few decades in the future, after things have fallen apart. Maybe now. Jim Haley is a private-eye who works for The Private Inquiry Office in San Francisco. In this case, his inquiries lead him to such places as "the wide-open sin town of San Rafael, run by the amateur Mafia (no Italians allowed) and "the Nixon Institute, where aging rock stars reminisce about the days when they still had hair."
I've heard some people say that Goulart's humor is an acquired taste. If so, I acquired it long ago. Well before 1970, even, and I found this book hilarious, also a little touching and sad. The satire is as sharp today as it was nearly 40 years ago. The book comes complete with raves from writers such as Philip K. Dick, and it was nominated for an Edgar, so surely I'm not alone.