On my car I had some "black marks." There was a black mark line on both of my mirros. Going in the same direction, same length. I asked the dealer to fix them. They said since it was on both mirrors, it was something they wouldn't cover. grrrrr!
I also had some black marks on my driver side door. I thought it was the paint scraped off from opening/shutting my door. Dealer said they wouldn't fix that as well.
So I wax my car. I take a buffer to it. The last thing I did was the mirrors. I didn't realize it at first, but the buffer took the black line out!!!

I was sooo excited!!

I checked the other mirror and it was gone too!!!
I opened the door, did some buffing and waxing, and got those out as well!! Now i'm dancing!!

But I couldn't fit my buffer all the way in the door.

Thank goodness some elbow grease and a rag got it off. I think this calls for celebration!!
Now the only problem I have is under the trunk lid. There is always a collection of dirt between the plastic panel and body of the car. Very messy. I need to come up with a way to prevent that. Dead Bugs, sticks, and leaves like to collect there.