For my personal taste the picture is a bit too much photoshopped, but the pic itself is not bad. Try to get the cars bigger in your pics for a start. The subject of a picture should not be too small. For me it seems that in your pic the subjects are the car and the dimmly lit sky. So one could have used a vertical format, to get rid of the not so important parts to the left and right of the car. This however is just a quick idea. So please don´t misunderstand me, I´m not trying to tell you what to do. It´s just hints based on some simple thoughts, as there are no "rules" in "arts".
The pictures are okay, and certainly not bad for a beginners attempt, but the photoshopped picture isnt anything pretty to look at to be honest...it is too dark as said before, and the subject is too small..theres a very good tutorial on taking pictures stickied in this forum..you should check that out.
Also if u cant be bothered to use the correct exposure while taking the pictures use photoshops Level tool (Ctrl+L). Bring the right most slider under the histogram to where the graph falls off to zero. if that made any sense lol if not PM and i can giv u a more detailed walkthrough.
Try experimenting with other filters...i have found that diffuse glow is a good one but cant seem to find a use for it lol
Have a look at my gallery aswell for ideas maybe..i photoshop all my pictures..before i put them on GTP: Toontoonizer's Gallery
GOOD LUCK on future pics..cant wait to see wat you can come out with next!!!