I recently experimented with earning money from a self-serve car wash, and I was surprised by how feasible it really is to make a decent income in a short time. Many people overlook this method, assuming it requires complicated equipment or a lot of startup capital, but that's not the case. The key is to understand the workflow and maximize efficiency. Most self-serve car washes operate on a coin or token-based system, charging small fees such as $2 per wash cycle or rinse. It might not seem like much at first, but when you consider that customers often do multiple cycles—for washing, rinsing, and sometimes applying wax—the total income adds up quickly. For example, if you receive $2.00 per deposit and customers typically use the rinse and wash multiple times in one visit, the revenue accumulates. My biggest takeaway was the importance of location. High-traffic areas near busy neighborhoods or shopping centers attract more users, leading to higher earnings. Additionally, ensuring the equipment is well-maintained and clean attracts repeat customers. Another useful tip is to incorporate additional services or products like air fresheners or vacuum stations to increase earnings per visitor. From my experience, keeping the customer experience positive encourages more frequent visits, which directly impacts your weekly income. So yes, making $2409 yen (approximately $20) or more within a week is quite possible with a self-serve car wash business if you focus on location, maintenance, and customer satisfaction. This method can be a great side hustle or small business opportunity for those looking to generate a steady cash flow with relatively low upfront costs.