[MarioBro88]

This is a terrible chop, I know, but I wanted to give you guys the basic idea, and I couldn't get it much cleaner. This is a chop off of the X6 spy shot.
EDIT: Now that I think about it, it looks like an X5.

original: C:\Documents and Settings\Compaq_Owner\Local Settings\Temporary Internet Files\Content.IE5\KLAB8XU7\2-bmw-x6-spied[1].jpg

chop:

 

[Gturismo1]

It's OK for a beginner. Just keep reading the wealth of tutorials. Learn things on how lighting effects metal, highlighting, shadows, etc.

Also, stop using the smudge tool.

Look around at other car images and see how light interacts with ridges and raised panels. Using a solid color up and down the whole car looks horribly fake.

Also, learn how to use the Pen Tool as it will make chopping bits and pasting them look much much cleaner.