pretty good.... couple flaws though... your better than most people with photoshop though so dont bring yourself down... just a couple things to try and work on with future sigs
1) on the left side near the back right tire of the car looks a bit too over contrasted.
2) theres just a random spot near the front right tire. dont know what it is.
3) no light source / flow to the sig
4) like everyone else said about the font.
5) no real blending in the background with the car
other than that the sig is well made. i'll give that a 7/10