I was there on the 1st of March this year and i've seen nobody that came to me this whole day.
No MP and no German police, so it's strange that they (MP) asked you to leave.
At which side of the airbase were you this day??
I was staying at the west-side. There is an footpath under the head of the runway.
I think this is one of the best places to stay.
There you are +/- 20m from the fence, so they can't tell you to leave.
You can get there to take exit Ramstein-Miesenbach, go to the left on the L363 and follow the way to the right to the entrance of the Airbase. At the roundabout you can go to the right and you can park your car at the left or right side of this small road. Then you've a nice view at the head of the runway. From there you can take the footpath to get an view at the platform and you can make nice pictures of landing and starting aircrafts.
I hope this will help you when you're going next time to Ramstein.
P.S: Some of my photos that i've made at Ramstein can you see at my website. I had bad weather this day, misty, cloudy and cold but with a lot of aircrafts.
Regards,
Roelof-Jan Gort
http://www.rjgfotografie.com
The Netherlands