In self-service car washes in use today, a customer drives his vehicle into a bay where there is located a coin operated device designed to provide a number of liquid solutions through a pressurized hose and applicator. The solutions often include such things as a soap solution, a water solution, etc., which may be selected via a selector switch and may be changed any time during the use of the device. The device usually works on quarters for an mount of time proportional to the number of quarters inserted. Given the choice, a typical customer would run the device for a short period of time to cover his vehicle with soap. Thereafter, leisurely clean his vehicle by hand without time pressure and, once finished, would run the device again for a short time to water off the remaining soap. This procedure, however, ties up the bay for an extended period of time and provides the owners with the least revenue.
It is for the above reasons that many self-service car wash owners have installed devices that require the deposit of four or more quarters before the device will operate. Once the four quarters are deposited, the device will run for the anticipated time that the average customer needs to complete his wash. If the customer requires more time, he may deposit additional quarters any time while the device is operating. Since most customers want to get the wash completed with the least expense, customers often deposit only the minimum number of quarters to initiate operation of the device--typically four.
While the customer may insert more coins for additional time, most choose to try to beat the timer and complete the wash in the time allotted given the minimum number of coins necessary to start operation. In so doing, many customers find they need a small amount of additional time after the timer has expired. However, inserting another four quarters to finish the wash, which requires say, one more quarter's worth of time, frustrates the customer. To this end, manufactures of self-service car wash equipment have installed digital time readouts which indicate to the customer how much time is left so that they may better gauge if additional money is necessary before the device shuts off. Attempts along these lines have also included horns that sound or lights that flash in the last remaining minute. These warning systems have, however, been expensive, subject to vandalism and difficult to maintain. Moreover, these systems have been largely ineffective in that customers hurry to finish when they hear the horn or see the flash of lights and still do not finish in time and must deposit four more quarters to restart operation. A better system is necessary.