Try and get a colour chip on "Petrol Blue".
Before I posted I Googled Petrol Blue Mercedes Benz and there is a pretty wide range of colours shown, mostly due to the competency of the various photographers.
An old mate of mine had a 280CE AMG (understood to be the first AMG imported into Melbourne and shown on the 1985 Lanes Motors stand at the Melbourne Motor Show). Amazing colour. It looked green in some light, blue in other light.
But those Mitsubishi colours are pretty good too.
"Street Machine" needs a regular "how to" page. Your car and processes sure would qualify mate. We don't all drive show cars.