<snip> I don't suppose you have a source for that info?
Criminal law class I am presently enrolled in. The instructor outlined how a series of court decisions since
Miranda v. Arizona and related decisions in the 1960's have eroded (in particular vehicles) the 4th Amendment rights discussed here. This was pretty much news to me, too, since I'm kind of still living in Miranda-land where court decisions are concerned. (This does
not include real estate a person may own, which is still in a much more protected category.)
As far as telling an officer they don't have your permission to search, please do, and I certainly will if it ever happens to me.....but that's unlikely to prevent a search if the officer decides to exercise their discretion, and you will almost certainly
not get a supervisor.
The dicey part for them comes when they stop you for a license plate light and then do a search that isn't authorized by you. Say they find illegal drugs— they can seize the drugs, but the drugs can't be used as evidence, so you're back to a license plate light. The officer may well face disciplinary steps over that, but
not an illegal search.
The instructors in my course are criminal defense attorneys, and say that charges in these instances often stem from diarrhea of the mouth. One must obey the orders of an LEO or face separate criminal charges, but "do what they tell you and button your lip" was what we were told— just STFU. Most people start talking out of embarrassment or because they're in a hurry and they just want to get it over with. Big mistake.