Nice shots Kent, oh and please check my gallery out buddy. Anyway some tips:
Blur the background out in most photo travel places.
Think twice, when using bling rims on most cars.
Try to get rid as many jagged edges as you can.
Oh, and Kent Shot 1 has some type of odd blur jagged edge. Like when a camera has low megapixels set, and shot 2 has the same blur jagged edges.
Like near the rear defuser, and on it. But that blur jagged edge, is mainly like, when too much noise from some higher camera iso levels shows up.