Washing a car is an operation not to be underestimated, great care is needed in order to avoid damages to the bodywork, this can be done using the 2 buckets technique and the right accessories.

The 3 essential accessories are:
a SAND FILTER, an anti scratch WASH MITT and a good  EXTRA DRY microfibre towel for drying.

The 2 buckets technique 

After parking the car (which cannot be hot) in a shady place, proceed with a good prewash, that allows to remove most of the dirt without touching the bodywork, this way accidental scratches are brought down to  zero

After rinsing the car, the 2 buckets technique can be used:
the first backet will contain water and shampoo, and the second only water and a SAND FILTER.

Soak the anti scratch Wash Mitt in the first backet and soap a part of the car, always starting from the top, after that clean the anti scratch wash mitt in the second bucket and rub it on the sand filter grit guard to remove most of the impurities.

In fact, by rubbing the glove on the Sand Filter grit guard all impurities collect on the bottom of the bucket, and the glove, being perfectly clean again, will avoid damaging the car bodywork. 

Then repeat the whole process for washing the entire vehicle and rinse it accurately, possibly by letting the water run from the top to the bottom, this way it will dry more easily.

Lastly, we can use an EXTRA DRY drying towel to complete the work in a perfect way.