It's great to know your laws when dealing with the Police... Even in my limited interactions back in college (they were there for underage possession of alcohol) they were trying to lead me to say things that would allow them to search stuff, and would say they're going to do something that they can't actually do (essentially just trying to intimidate a person into going along with it).
The funny thing is those cops were actually very friendly (one even saw a girl's Ugg boots or w.e and started singing "boots with the furrrr" haha), but that's just how cops are coached. In many cases the person is indeed doing something illegal, but the only way it's legal for them to find the evidence is essentially through intimidation. At the very least, they're careful NOT to let you know what rights you have.
Frankly, I think we need a Miranda rights part 2. You shouldn't only be read your rights as you're already being arrested, and cops should be made to read your rights as far as interacting with them goes ahead of time. Heck, that would also help to clear up what rights a person has to the cops who are reading it, as they certainly aren't lawyers themselves and often learn the trade from people who've spent a career bending the rules.