I am going to drain the green, flush the system with distilled water, then fill with the red. I can't imagine that the small trace amounts of green left in the system would harm anything. The guy that I bought the car from owns one of the biggest private MBZ only shops in Maryland. I was given every single repair record for the car. Judging by the condition of the car, I would find it unlikely that this guy would have put anything in the car that would be detremental to it's health.