well, keep at it. It's a thing that takes a bit of practice.
This forum is worth looking at :
www.cgtalk.com (MUCH better than smcars.net imho.just a higher level)
You can start a thread in the WIP:3D section, and get some good advice. And check out the other threads, you can really learn a lot by doing that.
I know I did! I haven't been on there for a while, but I don't think much has changed for the worse, so worth a try. (Actually I think you can find most of my models on there, and compared to some of the other guys' work, they really aren't much as you'll see).
Again, I'm really pleased that someone here is interested in 3D for real, not just rendering the LFS cars (almost always in the same boring way) or editing the LFS cars' mesh. Just my own view