Paint AM DB9 mouth

I always thought that a DB9 with a paint scheme from a Ford Mustang GT500E would gray metallic primary + darker grey metallic (or black) secondary (2 longitudinal stripes/mouth/mirrors) would be a good color

Red is a hard primary color to add to... white or black would be fine as long as some other feature on the car would be painted in white, dark grey, or black, for instance a longitudinal stripe (or 2) starting at the mouth, spanning the whole car (like on a Dodge Viper Generation 2-4), and maybe the pillars + mirrors.

Otherwise it might look a bit like you have spare parts on your car...

What I mean, if you want to paint it (say white) on top of the red it would be good that there were more than one white area on the car, and that some of them flow together (as in the white border on the mouth merges with the white longitudinal stripes on the hood, which continue on the roof and on the rear of the car...) That way it will look more like a factory special edition/factory custom color scheme than something done by hand...

Would suggest to refer to the N420 edition for the V8 vantage, as well as to the old Ford GT40, which also bore the "gulf" paint scheme (as the DBR9) before doing the project

Good luck