Your question made me ponder a lot to be honest. I was thinking how should I explain, car washing is much more complicated that you'd think. First things first, before the time you should work on your way of cleaning . Always wipe your car in circular motion with sponge/rug using shampoo or cleaning solution. This will help you maintain the paintwork for longer period of time . Do not use excess water while cleaning the salts in the water will form dirt layers on the glass surface ,it will also degrade your paint. Now this might sound unconventional but human urine is very good for cleaning . It removes dirt very easily and you can get a glossy finish, very effective on glass surface. Finally as far as the time of washing is concerned-Car wash near me ,washing during the day would be preferred because you can see your car in natural light and would be better for detecting dirt among other things.