I found a few more tidbits, including Mary Roach talking about Bonk on YouTube:
Barnes & Noble is showing this cover of the paperback version:
And Amazon is showing this one:
Here was the hardcover version:
VB: Was “Bonk” your pick for the book’s title, or did you want “Boink?”
MR: Bonk was my choice. Boink is a cartoony, silly word, whereas Bonk is almost onomonopeaic, or however you spell that word. Norton actually did some market research on this point. Most people have heard both terms, though more know Boink, it’s true. Those people will simply have to puzzle out what the book is about using the subtitle and the f–ing ladybugs.