It depends on whether or not you like police procedurals or not. "The Onion Fields" and "Echoes in the Darkness" are both nonfiction but the writing style is similar to his fiction work. I really love police procedurals (both books and TV) so Wambaugh scratches a certain itch for me.
I've got The Onion Fields" to watch yet on Netflix. That's the movie of it correct?
I just read my newest issue of Hemming's Muscle Machines. Best car magazine in the world if you love American Muscle.