I've been approached twice. Not stopped, not pulled over, both times just spoken to in a friendly, polite, interested manor. Both times (a year or two apart) while stopping at the lay-by opposite the Cat & Fiddle. The first time the Rozzers were already there when I stopped to put a jacket on and turn round to go back down. First time after an interested chat about the car, the traffic officer said something to the effect of good to see you enjoying yourself without being a prat, (I'd seen them up there, so was careful on the way up), and left me with the line; "seen your car round a few times up here, always good to put a face to a car..."
Second time the traffic car was actually behind me for a short while, pulled in behind me, and a few bikers, and circulated between us all just having a chat, letting us know they were around etc. The one that spoke to me did the same thing though, interested quick chat about the car, followed by a short bit of "advice".
Visitors to the Ponderossa up on the Horse Shoe pass seem to get the same sort of "professionally friendly" rather than confrontational approach a lot.
I do think the Police seem to be in a no win situation though sometimes. Practice the "dominate and control" method and the usual moans come out. Adopt a more softly softly approach and yet more moans...