Same thing's happening to me, no idea why. My 'type' of car is being stolen so they have to check my docs .... 24/7?? Oh please :os but enough excuse to cover themselves. It's harassment and intimidation - sometimes they're subtle, sometimes they try to scare me. Either way I spot them now - two people, any car (INC Taxis hun), they both sit too straight, the passenger keeps looking down at something, they talk sparse and businesslike, no laughs or smiles ... one day I'll crash watching the mirror instead of the road in front. They appear behind me from a side road I know was dark when I passed it, zoom up fast, then brake for no reason about 20' behind and pace me, I assume to gauge my speed. Then they pull beside me at lights, look in - seatbelt check? or see if I fit the description? or just nosey? But they won't move on green, I have to go first. Snails pull off faster than me. They keep following, and like you I go round in silly circles, and yeah they follow that too LOL. Eventually the super-sleuths realise I know they're there, they get bored and take a turning that leads straight back where we started - it's handy having them confirm I was right! They're irritated now though, you made a fool of them, guaranteed you'll get more behind you after that - accept it's gonna be another ridiculously slow journey and get what pleasure you can from their obvious frustration as you tootle along in your high performance car like an anesthetised pensioner. Other times I get the tag-team who are assertive, forceful and very obvious - they appear to be provoking me?? They go past me in the other direction, do a blatant u-turn directly behind me and tailgate me - illegal, very close, What The Funicular are they doing?? That goes on for a mile or two, then another shoots past me and does the same u-turn in my mirror whilst the first one overtakes me, way above the speed limit and then number two sits on my tail a mile or two more. One night they did that all the way home - 15 miles - 4 cars in all - I was shaking with the tension of driving that way by time I got through the door. Those ones are almost always two blokes in hatchbacks - corsa/vw/fiesta type things you'd usually associate with boy racers.
We must be on a list, pissed off the wrong person? I'm white, middle class, middle aged, female. I've no record beyond very minor possession and they only found that after stopping me every night for months (no exaggeration). One tried to pull me after a speeding stop couple years back, I wasn't interested...could it be something that trivial? Do they have private lists of people they just don't like? I no longer think that's impossible. A little bit of power .....
Take routes without speed cameras to avoid number plate recognition cams which are on them all. Get a personal reg from the DVLA - not a good one, a cheap one - change it, don't make more memorable :) There's sprays on the net that stop cameras reading your plate. Mud splatters play havoc too. I asked a solicitor what I could do, he also said change my plate immediately (interestingly he didn't for one minute suggest I might be wrong or look in the least surprised). Also told me to note down car reg's when they follow and/or stop me but that's hard when you're concentrating on perfect driving! Use the record facility on your mobile and say it out loud instead. If they follow you a lot you can get a car back window camera - about £100 - I'm seriously considering it.
I sound paranoid. I thought I was paranoid. But it's been over a year, I'm damned well not paranoid and plenty of friends have now seen it too. Got stopped last night - my car but my b/f was driving - they lost interest minute they saw him, said just confirm his insurance - he gave the wrong address and they said no, and then told him the right one! He repeated the address they gave him and they waved us on. Later I drove home, got followed by two plain clothes.
Bloody police state.