I am not trying to repair anything, I am not experiencing any coolant leaks this is purely a preventive maintenance issue. I have read the past threads on this topic, which include varying opinions and advice. Then add the instruction I received from the dealer (add all 6 tabs) and what I've read in my aftermarket repair manual (add three tabs but flush cooling system repeatedly until water is clear) and I find myself with more questions than I started with. But if the seal tabs are a good idea to add to new coolant in a N* with over 100,000 miles, then I will drain the system, not flush it, crush three tabs and place in the lower rad hose and fill with 50/50 mix of Dexcool and distilled water. Sound good, I'll wait for your replies, thanks guys.