This is obviously going to vary wildly by country, of course, and I’m sure your rights in, say, Northern Europe are going to be considerably different from your rights in, say, Saudi Arabia. So I’m just looking for a kind of general survey here.
Are you allowed to film police? Are you allowed to remain silent? Do they need a warrant to search your vehicle? Etc. etc. etc.
I grew up in Pakistan, and regardless of what my rights were supposed to be, the police and even more do the military, did whatever the tell they pleased.
I was in a car accident and minutes later I was in a police lockup with the police threatening to beat me up unless my parents forked over a fortune. Instead they came cover with my uncle-by-marriage who was a big-wig in the military and I was out lickety split.
This was during what was effectively a military government. From what I have seen and heard more recently things are at best marginally better, with the military having less direct influence in the affairs of ordinary folks. But the police are pretty rampant, corrupt and unaccountable.
In Norway you are:
Allowed to film the police (though individual police officers might think or claim you are not) and a recent verdict also confirms you are allowed to post such footage on social media.
You are not required to answer questions from the police beyond identifying yourself (name, dob, address, employer), neither as a witness, person of interest or suspect.
Searching a vehicle requires a warrant or a valid suspicion of a serious crime and a situation where waiting for a warrant is likely to lead to any evidence being removed or destroyed.
Etc. etc. is strictly forbidden.
But not etc.? 
In Canada, I’m not aware of any cases relating to filming of police, but I can’t think of any prohibition on it.
Right to remain silent? Yes, protected by s. 7 of the Canadian Charter of Rights and Freedoms.
Warrant to search vehicle? If on roadside, not necessarily, depending on the facts, what the officer has seen, any factors leading to urgency. If just sitting in your driveway, yes, warrant needed.
Right to counsel? Protected as long as you’re detained or under arrest; don’t need to be detained or arrested for interrogation, unlike Miranda test. Right to be advised of right to counsel upon arrest or detention, although it can be deferred in situations like roadside or other urgency situations, and kicks in when taken to the police detachment.
Not meant as legal advice, of course, just commenting on matters of public interest.
In the UK they changed the equivalent of Miranda rights to read “you have the right to remain silent, but if you fail to mention now something you later rely on in court it may harm your defense”
Which whatever the civil rights implications took away a punchy line from police procedurals.
So, does this mean that exculpatory evidence brought in after questioning is inadmissible in court?
I get the impression that if so, your defense counsel can’t bring new facts, opinions, or statements and that you have a one time shot to lay your proverbial cards on the table. . .
Tripler
But then again, all I know of British criminal procedure comes from Broadchurch.
No, it doesn’t mean that. It’s that if you don’t mention something early on, that may be cited by the Crown as a factor going to credibility.
Scénario 1: Bobbies question you about a robbery that occurred the night of July 10. You say « July 10 was the annual darts tourney at the pub and I was playing. You can talk to my mates! Here’s their names. »
Scénario 2: you keep silent when the bobbies interview you. At trial, for the first time, you call a friend who testified that he saw you at the pub that night. Crown closing address: « the accused had ample opportunity to advise the police of his alibi. And yet, it’s only at trial that a witness comes forward with this testimony. We submit that is a factor going to the credibility of this alibi. »
Ah, I see–thank you!
Tripler
Interesting, and I never thought about the weighty reliance on credibility. . .
I’m not a lawyer, but I believe in Canada, the police are under no “obligation” to tell you of your “right to remain silent” although you do have that right and further, if you want a lawyer present, you can have one there but the police still get to question you without a lawyer, you just have to know enough to shut up.
Here’s a good summary of the warnings from a police service in BC.
There’s the Charter warnings, where the police have to tell you the reason for the detention and the right to consult counsel, as well as the notification of Legal Aid lawyers if the person can’t afford counsel.
There’s also the common law warning that there is no obligation to speak to the police, and if you do, what you say can be used in evidence. It doesn’t use the term « right to remain silent », but that’s what it means.
If the person asks for counsel, the police must hold off and not question until the person has had the opportunity to consult counsel. That can be by telephone right away, or in person, or a combination, depending on the facts.
You are correct that once the person has had an opportunity to consult counsel, the police can again ask to interview them, but they must repeat the warnings (called « secondary warnings »).
If the person chooses to speak to the police without counsel, in spite of the warnings, that’s on them.
I’m no expert in these questions, but what I do know about Germany:
You have to identify yourself and show your ID to the police. If you’re unable to do and don’t tell your name, they can take you to the police station for further measures of identification. But you’re allowed to keep silent about anything else.
I’m not sure if the police has the right to search your vehicle without a warrant, but I do know that it happens all the time. An anecdote from my misspent youth: Together with two friends, about 25 years ago I got into a drug raid at an illegal techno rave, and all persons and my car were searched for drugs, including a drug-sniffing dog. Though we all had weed on us, the cops and their dog were farcically incompetent and found nothing. I don’t know what would have happened if I had refused the search though, I was too intimidated at the time to even think about it.
I’m quite sure you’re allowed to film the police, though there may be exceptions, but rather because of individual rights of the police officers that every citizen has about taking their picture.