maecrispy,
I'll give you my two cents, for what that's worth. For starters, I earn just under a six-figure income in sales, and while I have enjoyed detailing cars on the side, I've never had to detail as my sole source of revenue. In other words, take my advice with a small grain of salt
If you're making $75k a year, and it's a secure job (as 'secure' as secure is these days....), you'll want to evaluate a few things before you take the 'full-time detailer" plunge.
First, can you afford the almost certain pay cut? To make $75k a year detailing, you'd have to do 10 $150 details a week.....every week. While it sounds achievable, remember that it's 2 a day for 5 days a week. Of course, you'll have cancellations, rain, etc to deal with.
Second, I think there is some level of security in detailing. My small clientele is upper class, and they associate their car with status. They also see the value in 'maintaining their assets', so for the foreseeable future, I'll continue to keep working on the weekends. I can't say whether there's an ebb and flow to this business, because it's never been my primary source of income. However, I'm willing to bet if you fish towards the lower end of the market, you'll see business disappear in a bad economy. Even worse, they won't be loyal because they don't understand the value of your service.
From my own perspective, I'll continue to detail on the side. It provides me with a means of testing new products, and also allows me to teach my teenage son the value (and rewards) of hard work. Then there's that nagging question: Would I enjoy detailing as much if I HAD to depend on it for a living? I've entertained the thought of detailing full-time over the years, but haven't felt the urge (or need) to choose that direction.
Regards,
Ntwrkguy1