what are you looking to correct or improve on? i mean the main thing is light. the yellow street lights give you that yellow tint. leaving the lights on the car with a long shutter creates the blurry lights and colors the area around it. if your source light is behind your car, it will make the car darker or you will blow the light out. it really depends what you are shooting and what you are trying to accomplish. post processing helps a bunch. I try to keep say a street light or a building light out of the frame unless it is part of the picture like in the parking garage or the building sign. don't be afraid to crop either!
i like 12 too, makes that 6er look fast. only thing is the blue lines. i don't like when they intersect the car unless it is part of the picture.
shoot in aperture priority too if you don't already. expose for the car or whatever you want exposed and adjust your overall exposure if you want the picture a little more over or under exposed. depending how close or far you are from the car, f8-11 tends to be the sweet spot for most lenses giving you the sharpest picture. I try to shoot the same pic a few times and see what works best on my computer.
You can also shoot the same pic twice, exposing once for the background and once for the car. as long as the two aren't drastically different, you can layer the foreground into the background and have a pretty cool shot. its all your preference and what your style is though. can't please everyone so just please yourself
