Absolutely beautiful image. The paint looks perfect, the brake lights look perfect. Only two things I would change to make it even more realistic (for my own sense).
The ground plane scale could be much smaller. The way it is now, looks like a miniature car to me.
The dirt on the car. Looks more like finger print smudges. I would try to change it to something more like dust or fine road dirt.
But that's just my opinion.
Great work, by far.