Ah, beyond the wonder of dSLR...
Suggestions:
Learn to use the manual settings of your camera. The cameras of today are smart, but you are still smarter. This is especially true in low light conditions where the camera is more easily fooled than your eyes. You know how you want the picture to look, the camera doesn't.
On the same train of thought as the above, learn to use manual focus on your lens. The photos you posted were somewhat oof (out of focus) and that problem could be solved through manual focus.
If you want great photos, you need more than just a good camera, you need decent-good glass in front of it. Lenses are like the tires/suspension on your Mustang. It doesn't matter if you have 1000HP if you can't get it to the ground.
And last, but maybe not least, learn Photoshop!
Have fun with the toys! (Car and camera!)
