It certainly can be accomplished with the method you're using, although there are many other ways to go about it. In my experience, if you continue to use the method you've started with it will usually go a little faster and you'll get a cleaner mesh if you start from the nose and work toward the tail, instead of from the side. Also, don't include thing like the wheels as part of your outline... make them their own object instead. It will go much smoother.
As far as alternative methods, the method I personally use most often is called the box modeling method. Basically, you start with a box, turn on subdivisions, and continue extruding surfaces until you get the shape you want.
I posted a short video of a very rough car model so you can see an example:
http://youtube.com/watch?v=uEfDw8YMxKo