Coin operated vending machines and vending methods for self service car washes that vend different commodities or services at a united price. The machines vend vacuum at different speeds, and spot remover or fragrance. Each machine has a computer-controlled, multi-segmented bar graph providing an analog indication of the amount of a vend that remains, and a dot matrix system for displaying text messages. The bar graph has multiple adjacent segments each having multiple cells that contain separate LEDS of different colors. The bar graph provides a relative, analog indication of the amount of a particular commodity remaining to be vended. When a vend starts, all of the bar graph segments are illuminated and as vending continues, bar graph segments and individually cells are sequentially decremented. Different products are associated with different colors. The customer may switch selections while a credit balance remains, and bar graph illumination is reset to 100%.