You took the pic from a great perspective. But the lighting is hosed, there's no detail at all in the blacks.
The reflections in the passenger side of the car and windows really weakens the photo. Get a polarizing filter for your lens. The reflections happened because you had the camera positioned in the 'family of angles' (like shooting pool). A polarizing filter would have helped with the reflections somewhat and would have helped a lot with the tonal density of the sky and background.
The picture would have benefited in many ways if you had used 2 or 3 speedlights and a location with a less busy looking setting where you could have taken your time to pull it all together. Using flash allows you to control 2 different exposures with one shutter release. It would have allowed you to really make your car 'pop' by having it lit nicely (controlled with aperture), while also rendering the background dark (controlled with shutter speed).