Well, after decades of publishing automotive how-to books, Haynes has shifted to a more social realm. As shown above, it's now possible to buy a Haynes guide to sex. It's titled SEX: 16 Years Onwards, All Models, Shapes, Sizes and Colours., and branded a "Haynes Owners Workshop Manual."
It sounds like a Mad Magazine spoof, but this is for real, an alternative to the "For Dummies" books. SEX is part of a series, which includes Child, Man, Woman (with the word Owners crossed out in the brand), HGV Man, Baby, Toddler, Cancer, and other health issues. (And just for fun and fascination, there's a Hayes Owners Workshop Manual for the Supermarine Spitfire. Definitely different.