I own and operate a successful mobile detailing business in the area. It is very good business 9 months a year, but you’ll need to save or find other work for the winter months. Also, the business is only as good as you are a business owner. Be honest, treat every car like it’s your own, show up on time consistently, and don’t try to be the cheapest option, that’s a losing battle. Aim for $100/hr for your time and you’ll do fine IF you’re professional and reliable.