Best motion detection settings

i just installed the #Floodlight Cam Wired Pro.i have my motion detection set to people and its doing a fine detection of people coming and going. i am confused though as to why it is not detecting the Garbage truck and garbage collector?i have tried setting the "People only" off, but now im getting every vehicle that passes by.just wanted to know what ideal settings i should be doing. i had this camera up so i can get a glimpse of our kind neighbor who likes to walk their dog and poop on our lawn and leaves it for me to pick-up or step on when i mow the lawn. this way if i get video clip of them, maybe i can be subtle and remind them via social media to pick up after themselves. thanks.