Following these simple steps from eartheasy.com, you can save up to 150 gallons of water each time you wash your car:
Clean the car using a pail of soapy water. Use the hose only for rinsing – this simple practice can save as much as 150 gallons when washing a car. Use a spray nozzle when rinsing for more efficient use of water. Better yet, use a waterless car washing system; there are several brands, such as EcoTouch, which are now on the market.
For 24 more water saving tips and home water usage statistics, click here.