Tell the damn truth.
I come from what was considered a "rough" area of London. My schoolfriends were all police-hating idiots. Even through to today, I've had to remove people from Facebook because they were doing things like suggesting to "fight the pigs" when it came to the London riots. Just the terminology used tells you EXACTLY what kind of reaction they would have to being pulled over, and precisely WHY the police bother them so much.
I've been pulled over by the police just as much. I have a tendency to drive old bangers of cars - legal, but they look scruffy and even I would admit that I'd pull them in "just to check" if I was a police officer. Fact is, I know they are legitimate and roadworthy or I wouldn't be driving the damn things.
But when pulled over, I don't start yelling. I'm not all sucking up, either, I just tell them the truth. If you have to lie to a police officer to make things go smoothly with them, then maybe that in itself is a kind of retro-active JUSTIFICATION for them to have pulled you over in the first place. They have the power to pull over anyone for anything, of course they have to or they couldn't act on suspicions. And if you have had to LIE then it meant that you were doing something you SHOULDN'T have and that would be of interest to them.
I've had any number of interesting conversations with police officers where I could quite easily see them tend towards the "It's close enough, let's nick him" kind of attitude if they really wanted to. Fact is, I tell them the truth.
"What speed where you doing there when I pulled you over?"
"I honestly have no idea."
Is that an admission of driving without due care and attention? It could be interpreted as so. Did they have speed-measuring equipment on their vehicle? I have no idea. Probably, because it was a fancy ANPR vehicle with all the cameras and he'd been following me for a while. What happened? Nothing. "Okay, thank you, I'll let you get on your way, sir", after checking documents.
Pulled over after a police car spotted me and obviously "targeted" me from a whole queue of traffic. I'd even tried to let him out in front of me as he was joining traffic and he waved me in front of him, then pulled me over a mile up the road.
"We just pulled you over because your car looks like it's had a hard life, doesn't it, Sir?"
[His colleague walks around the car, inspecting it while we talk]
"Yes, I know. I buy cheap cars and run them into the ground, officer, it's easier than trying to buy a car outright when you have no money. But I have a full MOT here, done yesterday".
[Officer checks paperwork, asks me about my job - IT Manager for a private school, which could probably be assumed that I *could* afford a car, asks me where I'm going, where I've come from, etc.]
"Okay, sir, it says on here that X, Y, Z are advised. You should get them checked out."
[X, Y, Z are not MOT failures, but an MOT pass is not a guarantee of roadworthiness, so advisories are put on for potential roadworthiness issues. He doesn't even bother to look at them]
[Officer walks away after a nod from his colleague. Turns back to tell me to be careful when rejoining the road, spots a broken rear light - how the hell it passed MOT I have no idea - and both our eyes are unconsciously drawn to it as he speaks. Officer smiles.]
"Sorry to inconvenience you, sir. It appears you were missing the mandatory duck-tape on the bumper."
[Gets in car, drives off back to the spot he was sitting at before I came past - the duck-tape on the bumper is a reference to the type of car I was driving because you ALWAYS see them in the worst state of repair with bits taped back on]
I got stopped driving back from Europe to the UK late at night. Late, single male in an old, knackered car, was chosen from a line and pulled over for a customs inspection.
I was asked who owned the car (me) and how long (I said about a year). He asked for documentation of the car, it was already on the passenger seat because I had it together with my ticket for the ferry and my passport. (Note, I have no legal requirement to carry anything on my person, not licences, not documentation, nothing, nor to provide them there and then - I believe the law says 48 hours at the police station of my choice - but if I have them, why wouldn't I provide them when asked by a police officer?). The car was actually mine but it was in my ex-wife's name - at a different address - until just a month before when we'd bothered to change it over. That rang an alarm bell but I didn't realise until later why.
I was asked where I'd been. I'd been travelling around Europe with friends. Which friends? One had gone back to Australia, the other two were in Germany still. Contact details? Provided them, they couldn't get through (at 3am, not surprising). Did I have hotel bookings? No, we were doing the hostels at random each night wherever we ended up after a day of driving. Any receipts? No, the agreement was that I drive and pay the fuel, and my friends pay for the hostels and food and stuff. Any credit card receipts? I don't keep them, but we found only one, for fuel, that I found in the side-pocket where I'd just shoved it. Any food, cooking equipment, camping equipment? Just snacks, it wasn't that kind of holiday, we were eating out at restaurants, driving around during the day, and sleeping in the nearest hostel. How long for? The whole month of December. What about Christmas? I came back one day for Christmas and then drove back out to the friends in Germany again (and so have been off work for a month, and flitting back and forth to Europe on a regular basis...). What countries did I go through? France, Belgium, the Netherlands, Germany, Czech Republic, all sorts.
So all I had was an old, knackered car with just a backpack in it, no cash, no receipts, no contact with these people I travelled with, not even circumstantial proof of where I'd been for the last month, driving a car across borders for a whole month and then into the UK from the continent (which is a notorious spot to do smuggling of alcohol and other things), in a car which is registered to someone else and which I say I've owned for a long time. Sure, innocent people do that, but not surprisingly, the questions go more in-depth.
Five officers swarm over the car, searching it and I'm asked to get out and sit on a chair next to it and answer some questions. 3am, bloody freezing, middle of winter. At all times, they are polite, and considerate. Why wouldn't they be? Not a pleasant situation, even for them as they search through sweaty unwashed clothes, but they are doing their damn job. Again, I think to myself "Well, yeah, I'd check me too!".
At one point, an officer sits in the open boot (trunk) of the car to have a look inside and I have to say: "Er, sorry, not being funny, but you want to be careful - that door doesn't stay up properly and it might come down on you." They thank me. Then I see their brain ticking over. Then they are unscrewing the boot door panels to see if there's anything inside (no, the gas struts are just weak, so it doesn't stay up, that's all, but again "Yep, I'd check that as well!").
Nothing found, and soon after, I'm apologised to and sent on my way.
I got pulled over driving at 2am over the border to Scotland. Obviously just a "we'll get the tourists" kind of setup (there is no real "border", not a physical one, but the start of Scottish jurisdiction).
Had four people in the car, only one of whom spoke English. Tell them what's happening (relatives from Italy coming to holiday in Scotland with me). "On your way, sir."
Broke down on the motorway. A brake pad retaining mechanism failed without warning and fell into the brake disc (brake pads were about a month old). All I knew was a HUGE clonk and then scraping noises and massive drag and pulling to one side. Pulled the car over, put a hi-vis on, placed a warning triangle, phoned for recovery.
Police car arrives a minute later, after the CCTV operators spot me on camera. Police officer has a word to ask what happens. I tell him the brakes have some kind of failure and I'm not sure I can rely on them to stop or just jam on at any time, so didn't want to go any further. The usual questions, all answered politely. He escorts me around the corner (in a way that I hit him rather than anyone else), where there's a hidden exit and a safe place to wait for recovery. He leaves me there and goes on his way. He could QUITE EASILY have done me for a faulty car, and it could have been CATASTROPHIC if it had fallen slightly differently and pulled the car more, at 70mph, on a busy motorway, and even though I couldn't have seen the problem during normal maintenance.
Nothing, because he saw I was honest, and reasonable, and not causing him trouble.
At any point, I could have screamed and shouted and alleged all sorts of discrimination, or whatever. It wouldn't have helped ANYONE. At any point, the police could be seen to have "reasonable cause" to investigate further or do more. They didn't. At any point, they could have been nasty without even going outside their job specification. They didn't.
So either I found several dozen police officers who are the "nice" ones, waiting for people to drive past and then targeting and collaring me, or most police officers do their job when you are nice and honest with them - even if the information you give them has cause to give them suspicions or even could be used against you. I could have gone for the "silent treatment", of course, at any point. Would it have helped? No, not really.
Don't be a dick to these people. They *CAN* make your life hell if they really want to, by nothing more than their job. And when it's 3am and someone is breaking into my house, or the people in my neighbourhood are rioting and setting houses on fire, they are the ONLY people who have any sort of obligation to turn up and do something about it.
Sure, we can all cite cases where someone was honest and truthful and it cost them, but in the grand scheme of things it's the only common-sense solution.
Be honest. Be truthful. Don't play legal games. But, most importantly, be legal. And then you won't have ANY problems, beyond what you would have had anyway.