99prixgt, my Dex-Cool looked nasty at the radiator cap and in the reservoir, but to be honest, when I was draining it, it seems like it was more of a "surface film" than anything. Everything else was coming out plain ol' pink. I did spray off some gunk from the walls of the reservoir, radiator hoses, and the top radiator "neck" where the cap goes.
Makes me wonder if it was replaced shortly before I bought the car a little more than a year ago. At the time it was an 8 model year old car with only 38,000 miles, but the stealership I got it from may have flushed it and thus the reason for it not being really horrible on a 9 year old, 54K mile car.
