I've always had friendly exchanges with police too. There are some cops, and some areas where cops are more guarded, and it often has a lot to do with the behavior of the person pulled over.
I've been pulled over and police have been careful while asking if I am armed (they'd know I have a carry permit from their dispatch) sometimes I am, sometimes I haven't been, but under both circumstances I acted relaxed and friendly, with my hands on the wheel until told to dig for my license.
times have certainly changed.
many, many years ago I was stationed at Camp Lejeune NC. I was parked by the river one afternoon with my girlfriend finishing a fried chicken dinner. as I lit up a cigarette, we were suddenly surrounded by a bunch of guys with guns screaming a variety of commands (POLICE, GET OUT, DON'T MOVE, HANDS UP, etc).
I told one of them on my side (my GF was driving) to show some ID before I would get out, and he slammed his ID on the windshield to show me, so I slowly got out with my hands in plain sight. (My GF on the other hand just got out the first time one of these clowns in civilian clothes yelled "GET OUT". I gave her hell for that bit of foolishness)
About a half-dozen very wired cops (as I now knew them to be) were standing around panting, pointing guns at us as the Sheriff walked up. he looked at us, looked at our military IDs, and checked out the car before remarking, "Good job boys, looks like we caught a couple of chicken eaters". As he let us go, he told us they thought "drugs" were being used at that location so they had it under surveillance and when I lit a Camel they swooped in.
nowadays I might have been shot first for demanding police ID before I complied with their demands.