Spot the yellow balloon

As prices for petroleum rises globally, it is getting increasingly difficult to maintain a vehicle. In South Korea for example, there is a huge demand for oil and with the known fact that the country is primarily devoid of oil, it is even more challenging for car owners to cope with the increasing cost. Korean petroleum and refinery, S-Oil, decided to help drivers save on the cost of petroleum by coming out with a stunt together with advertising agency, Cheil to launch an interesting stunt. They raise bright yellow balloons in each parking space. Whenever a car parks in that space, it will case the balloon to drop. However, when the vehicle leaves the lot, the balloon shall rise once again. This give drivers visibility and early detection to an available space in a rather dense parking area. Thus, saving time and petroleum as drivers could now easily spot an available lot from afar. Clever yet budget effective solution.