Am I missing the point of this thread? The OP asks a question and then immediately answers it in the negative. Also, why 6 races? Surely McLaren won the first 11 races of the 1988 season and that's the unique thing? Can someone explain to me please?
I'll try my best to explain to you. In all honesty I could not answer the question in the positive, however immediately and hard I tried. No great mystery why the season's first six consecutive wins were chosen: that is what had happened in 2014 until race number 6.
So, back to McLaren who won the first 11 races of 1988, isn't the answer, "no, six race wins is not unique"? Again, am I missing the point of the question?