I had also visited Colonia Dignidad.  My visit was in late June, 1979, and I was researching material for a non-fiction book on the "Fourth Reich", which book eventually became "Unholy Alliance".  
During my visit, on a Sunday morning, my car was surrounded by armed men and my way out was blocked by the infamous white Mercedes. My passport was taken, my film confiscated, and I was subject to a kind of informal interrogation by Paul Schaeffer himself.  My driver was terrified, and could hardly answer the questions of the other security personnel: "How many are there?   When did they arrive?" amid statements that "We have to be careful of the diabolical intentions of these Israelis."
Of course, I am not an Israeli, I was there alone, and had  only arrived early that morning in the neighboring town of Parral.  The entire story is told in my book, but to summarize:  the people of Parral were terrified of the Colony in those days.  They objected to the presence of German nationals on an estate that truly was "a state within a state".  The local carabinieri were very clear about that.  And, once my visit was over and I was released, I was virtually escorted out of the country ... thus implying a very strong connection between the Colony and the Pinochet regime.