Suggest you using WORX high pressure water gun which is very efficient to save time and man power. In addition, you use electric blower to dry your car to be more effective.
We have 4 cars ( we live in US ) and my hubby has been washing then waxing the cars but its major work, especially the waxing part. We stopped doing that a few years ago and just brought them to the car wash. We are getting old and lazy haha.
My way to car cash is simplier, I use: Turtle wax & shine, after watching with water only, spray it and dry with micro fibre towel. Super shine and smooth, no need to wax. WD40 degreaser, all difficult areas to wash, e.g. tyre wheel, brake dust will be removed and look clean. Turtle wheel shine, spray to a paint brush, paint to the rubber area.