Some great work here--one suggestion, if I may? It would be great and very instructive to the enthusiastic followers of this thread if you would post the "hows" of how you are completing your model here. For instance, what techniques did you use to make the molded-look of the firewall?
I also have a passion for old, rusted cars--here are some examples of my models--enjoy!
"Lair of the Rust Bunnies"
"Checkered Past"
If you look at these work blogs, you'll see what I mean about showing your methods. It really helps people to see what you're actually doing. Pass along the knowledge!