It's on the right tracks, but for a hardsurfaced vehicle the smoothing is too much. You need to add an extra (very small) extrude to things if you want them to stay sharp. Look at the pieces that come out from the side (inbetween the two wheels) those need the extra extrude.
Also with your threads it's better not to be too misleading in the title. PC isn't a good name for a thread. Do you want me to re-name it for you?
Alan
Technical Director - Framestore
Currently working on: Your Highness
IMDB