The tail of the cruiser (right side when viewing sig) can be darkened more, maybe add a slightly transparent copy of the background layer above it using a layer mask.
also, on the right-front horn, there is too much light compared to the angle of the lightsource, try darken that one and increase the light on the left side.
The typography could be improved, but atm i cannot figure out a font that would fit it perfectly, just try around, or add some effects to the typo.