Unless your car is a true race car and ONLY sees track time, you need to stick with the 50/50 for street use. WaterWetter is AWSOME when used properly. By that I mean, if you are on the track, run straight water with a bottle of WaterWetter. On the street go with the 50/50 and add WatterWetter.
Don't know what the last guy was talking about in regards to "gunk".
I used it both in my old racecar and street car with great results.
Recently I blew my headgasket, and WaterWetter was one of the main factors that kept my motor from overheating and warping.