You might not want to show my post to anyone you are trying to convince that people having their cars detailed.
First, I have been around a looong time and know a lot of people.
I don't know of one person that ever paid to have their personal car detailed.
In fact, the only professional detailing I personally had experience with was the company I worked for and then it was only just prior to selling the vehicle.
I have friends in the used car business and one does his own clean-up which I don't consider detailing. Another has it done by whoever he can get the cheapest price from. Not the cheapest price for a good job, just the cheapest price, period.
While I love taking care of my own vehicles, it does seem like a tough way to make a good living.
Evidently several have been able to do it, though.
Sorry I couldn't be more encouraging, but I think it would be a good idea to try it on a part-time basis before I quit a full time job with benefits. Talk to someone in the business about the associated costs that are often overlooked. Even if you are mobil, when you take all your expenses into account, your health insurance, your business insurance, your self employment tax, book-keeping fees, vehicle depreciation, equipment repair/replacement, the extra cost is probably about $25,000 a year. It may sound like a lot, but list it all out and see what you come up with.
Charles