Damn, looks like I need to setup shop in Cali, lol.
I've really only been doing this as a hobby for about 3-4 months and using a rotary for almost two years. I've recently started doing this as a side business since I'm starting law school this August. Things to ask is what do they use on the paint as far as a rotary or a dual action polisher. A DA is much easier to use and won't damage anything in a novice's hands, but it takes a lot more work to get the same results. The rotary will get the job done faster and easier, but can also cause some damage if not used properly. Also, if your not using halogen lights to light up the work area, you make think you've done a good job until the car goes out into the sun and all the halograms show up
That's a big problem in a lot of dealerships that claim to detail. My advice is to ask to see some before and after pics of some of their work. Be prepaired to pay $200-$500 depending on how bad the car is, where you live, and how much is being done. Make sure they actually correct the paint and not just use filler waxes and glazes that will wash off in a month. Also make sure they use a paint sealant and not wax. It may be a little more $$, but worth it. Paint sealant will last 6 months-year compared to wax that will be lucky to last a few weeks. I personally like Zaino because of their ZFX system. It's not cheap, but shortens cure time to 30-45 minutes. Usually paint sealants take a couple hours to dry, then 24 hrs to cure before adding another coat. The ZFX uses a curing additive that you add just before applying. It allows a full cure in about 45 minutes, and you can do 3 coats in a 24 hour period. LOL, now I'm sounding like a Zaino rep!