My brother only uses Proshine stuff. Says it is the best you can buy, and it ain't cheap. Uses it on his Jag XKR, every Sunday, (takes about 7 hours as he details it) but his car is literally showroom condition. Water doesn't bead off it; the drops stop about an inch away, look at the car, and then move laterally till they are out of the path of the bodywork, and then fall to the floor!
I admit to being hopeless at cleaning my car. Turtlewax wash and go, then hose off is about all I do. Generally just don't have time or inclination.