i myself own a black car and dont have access to shade. this is what i do
firstly,
autogeek.net prob one of the best car detailing sites/shops. loads of info on how to clean your car.
- work either very early in the morn or late afternoon when the sun is lowest. never when the panels are hot (in sun or after a drive)
- wet the car
- start cleaning, quarter of the car max at a time. rinse entire car to keep all panels wet
- once entire car is clean, give it a final rinse to wet all panels again
- i use one of these
squeegees which removes bulk of the water and doesn't scratch the paint
- then use a nice thick towel such as
this to soak up remainder of the water. don't use a microfibre towel as they dont have much ability to soak up water and may cause scratches due to dirt getting trapped in the towel as they dont have any plush for the dirt to hide in.
if you havent done a clay, sealant and wax and cant be bothered doing it yourself, best to pay someone. then like you said, you can maintain it from there.
hope that helps