No not at all. Everybody interprets things differently. A lot of the guides on DW state to pre-rinse the car with an open ended hose so that the water sheets the loose dirt off, and the same for rinsing after the wash - yet you see all the professionals posting in the studio and they use a pressure washer at all times. Its like wheels, some people do them first, others do them last - the end result is always the same.