the short version of events here:
went to fill up in tesco yesterday morning
while filling up, some fella walks over and starts looking at the car
"you do know your front number plate is illegal don't you?"
"how do you mean?"
"no front number plate is an offence"
"it's in the windscreen, as you can see, the bumper is freshly new and it's still got bits missing from it, so for the mean time the plate is nclear view in the windscreen"
"is this your car?"
"yes"
"got any documentation on you?"
"why do you ask? the car is legit, it's not as if i'm going to do a drive off is it if that's what you are worried about"
"i'm a policeman" and with that, he's whipped some sort of id out of his pocket, flashed it at me and the put it away again "you need to write down your details and i'm reporting you and you'll have to pay a fine"
and then he hands me a bit of paper form the till to jot my details down on
"no official bit of paper then to write the stuff down on?"
"just write your details down on there, name address and postcode"
"so you aren't going to give me anything official in any way shape or form, just want to have my details?"
after all this has occurred and i'm feeling just a little pissed off, i go to pay for the fuel
and this cheeky fooker is sitting in the cubical
"i didn't think you were allowed to have 2 jobs"
"i can have 3 jobs if i want "

so, what's the crack?

anyway, as soon as i get a decent reply, i'm off to the cop shop to report him, and if i don't get a decent reply, i'm reporting him anyway

shouldn't he have announced himself as an officer in the first place?
no official paperwork? how does that sound?
unwilling to give me his number, thought they were supposed to?
flashing so id without letting me have a second look at it?
second job?
no tesco id either
can off duty coppers do this sort of thing?
etc
etc