From experience I have found that using TFR on similar coloured vehicles helps bring it up once you hit it with polish.
I always mix it but nothing like as much as I would now its been polished.
I had been a valeter for about 6 years, I had my own place for 3 years doing it but stopped not long before the foreigners took over all the garages in my area. Not a bad job to have and great when you get results like that.
Oh and thanks