Caught speeding

Guy driving his car on his way to work thinks to himself he'll have some fun and floors it. As he roars down the street he comes up to a bridge and at the last second he see a policeman peeking out round it with a radar gun and although he jams on the brakes but its too late and the copper flags him down.
'Do you know why I've stopped you sir?' says the officer,
'I think I do' the guy says,
'You where doing 60 miles an hour in a 30 zone, what makes you think you can do twice the speed limit?'
'I'm really sorry officer' says the guy, 'but I'm late for work'
The cop gives him a disapproving look and says ' And what may I ask do you do that is so important you can drive that fast?'
'I'm a rectum stretcher officer'
'A WHAT?!' says the copper,
'A rectum stretcher'
'And what exactly is it you do then?'
'well' says the guy, 'I start with one finger, then two, work it a bit more until I can get three and four in, keep going till I can get a hand in, then both hands, then I start to really stretch it, right up until its six feet wide'
'SIX FEET!' exclaims the copper,
'Yes officer, six feet'
'and what may I ask do you do with a six foot ********?'
to which the guy just smiles and says
'YOU GIVE HIM A RADAR GUN AND STICK HIM BEHIND A BRIDGE!'