I think there are so many cars out there that AREN'T taken care of, washing your car with ANYTHING will make it look brand new, even if it's twenty years old! But for my smartie, I do the following:
For cleaning / polishing the windows, I use the tried and true method of
Windex and newspaper. The newsprint is a polisher, believe it or not and works very well!
Then a little RainX on the windshield and it's good.
For the body, regular Wallyworld car shampoo or detergent, then tried and true Turtlewax. A good shiny, new look for not a lot of $$!
~Jas...