To answer your questions:
1- Yes any kind of buffer action which removes swirls and imperfections is cutting into the clearcoat. However, the way a dual action buffer rotates minimizes the risk of damage to the car by an inexperienced detailer.
2- I would only use a Rotary buffer (circular rotation with more risk of burning through the paint) on vehicles with heavily scratched and damaged paint and only experienced detailers should be allowed to use a rotary buffer on your car. A dual action buffer (rotates and oscillates at the same time) is a much safer alternative and gets the job done just as well IMO. I won't say it is fool proof as to burning the paint but it definitely is much safer to use. Your new 7 series doesn't need more than a dual action polisher and it ABSOLUTELY rises to the level of "paint correction"
3- I honestly don't know how much shops are charging but I've heard of shops charging from $600 to a couple thousand for a complete paint correction job. I've done my car myself and it was a whole day ordeal from 9am to about 8 or 9pm at night. Some shops might keep your car for a couple of days.
Here is an example of the process:
http://www.luxury4play.com/detailing...flections.html
Hope this helps.
Lui
