About 5 years ago we had a major hail storm and my wifes car got hammered. It probably had 30 small dents. Took it to a car dealership that had a company called Dent Wizard set up shop and when they were done you couldn't see any of them. We were very happy. So IMO I would try it. Good luck.
They will stick a rod down through the glass opening and tease out the dent, had one taken out of my roof through a rear dome light.
I watched him do a 350Z door that had a mean door ding on it before he did mine. I drove back and gave him some bar delrin, he said he had lots of ideas for it.
Black should be easy.
Each shop's ability is dependent on the skill of their technicians. Find one that has a good reputation or one that's referred to you from a previous customer.
I had someone put a nasty ding into my Mo along the crease on the front passenger door. It was pretty deep. The guy pushed it out using a long tool slid down the window opening (as another mgthe3 pointed out). He was able to get it out most of the way, but because it was on the crease, it wasn't perfect. Despite this, I was happy with the work. I don't think anyone could have gotten it perfectly and he did warn me in advance that it would look really close, but if you knew where to look, you would be able to tell. He charged me about $100. That seems to be the going rate.
The "rod" is actually a long piece of metal bent into an L shape at the end with a handle on the end. Some are bent into a J shape. They are kind of like a long screwdriver that's bent over at the end. The technician that fixed my ding slid the rod into the window opening and gently pushed out the ding from the inside. A skilled guy, like the one that worked on my car, will be very careful and push only a little bit at a time to gently work the ding out. His tools were also wrapped in some type of tape - like adhesive tape - to provide a more blunt and cushioned surface on which to push the ding from the inside. I don't believe there was any damage to the inside skin of the metal in my case.
I wouldn't be so sure its such a short time for training. If you've ever tried your hand at dent reduction, you'll find its not as easy as it looks. My vehicle prior to the Murano was a 1994 Chevy Camaro. Towards the back, if you opened the truck, there was a storage area for the jack and spare under a plastic cover. Towards the outside of the vehicle was simply painted sheet metal. I had a ding in that area and tried to pound it out with the rounded end of a screwdriver and a rubber mallet. My access to the inside at that point was as good as you would ever get on any car. My attempts at ding repair didn't work so well. The professional guys that can make dings disappear well have definitely had a lot of training and/or practice.
They have many shapes of rods and like I said "tease" out the dent. They work in tiny tiny areas at a time. Afterwards, he took out a mallet and several different shapes of delrin and tapped very tiny highspots back flush. He used a florescent light (even in the blinding sun) to look at very shallow angles of the area he was working.
He was good. He was so good that he was hired by the dealership permanently from an outfit that used to do the work for them. Metal work is an art form, you either have it or you don't--and it is quite obvious to the decerning eye.
I am a fan of Japanese swords, especially the ones made before the 1800's. Here you get to see why a skilled polisher gets $2000 for one sword polish....and you also understand why some swords fetch upwards of $100,000. Once you understand the metalurgy and the skill that goes into one, you are amazed with the beauty.
I had the small dent removed this morning. After 30 minutes its completely gone. The tech did a great job. He told me he does 2000 cars a year, after the 8 weeks of training you come out with limited knowledge, and only hands on gives you the tricks needed to make it successful.