Late to the thread, i recommend California Dent Works in Pleasanton, the fixed a nasty bumper dent and blended in paint on my Panamera seamlessly i was very impessed saving me thousnads as RJ Paint told me to replace the whole rear bumper.
http://www.yelp.com/biz/california-d...s-pleasanton-4

For those of you in SF, Precision PDR did a good job at fixing the door dings I had on my front fender. Quality of work and price was good.
http://www.yelp.com/biz/precision-pa...-san-francisco