Whether a weekend warrior or a full-time professional detailer, several factors need to be considered if you plan to work on a client's vehicle. First and foremost you need to be insured. This could be as little as a few hundred dollars a year for just general liability or much more if you plan on driving the vehicle at any time or even storing the vehicle at your facility be it a shop, garage, your home, ect. You never know when something could happen, and there is a possiblity of someone attacking your personal assests in a lawsuit. I'm sure you wouldn't want to lose your home because you're uninsured and someone sues you after their car caught fire while in your possession, or something to that effect. Next is you need to be properly licensed. How you set up your business, even if just a one-man-show on the weekends, could also avoid the possibility of your personal assets being attacked if you set up as an LLC or another incorporated manner. And finally, if you plan on working on another's vehicle you need to be aware of OSHA and EPA guidelines. Fines for violations could add up in the thousands of dollars and these guys typically don't care whether you do a few cars on the weekends or 60 cars during the week. If you are operating a business, (and you are if you're charging money and working on other people's vehicles on a regular basis rather than just the "I detail my parent's cars a couple time a year") then you gotta follow the rules, plain and simple.
BradUF, just to answer a couple of your questions. As a mobile operation, sometimes it's necessary to polish and seal a vehicle in direct sunlight, however, I always try to find shade or will sometimes use a canopy. There are alot of products out there that are rated for full sun, and while using those particular products...I've not run into any problems working in direct sunlight. As for the machines, yes, you can make improvements to paint using a DA polisher. That being said, you simply cannot achieve the same paint correcting results with a DA as you can with a high speed polisher in most instances and in the same time frame. Both the DA and High Speed Polishers are relatively inexpensive and can pay for themselves within your first few details. If you're really serious about doing this, I would consider investing in some training and after you build up some funds, consider purchasing an extractor or better yet a vapor steamer. You'll not only see a world of difference in the quality of your details, but will also save you much time and money in the long run. Just some things to consider if you decide to move forward. Good luck.
Matt Williams
Silver Lining Detail