A quick and simple method to get rid of the plastic new freight car look is to spray a light coat of Dullcoat.  This will take away the 'toy' train look of your layout.  If you don't have any Testor's Dullcoat you can use any Matte Finish spray to get the same results.  Just a simple spray to each side and let dry.  This can be done to any plastic kits also.

Micro-Trains Military Barracks Build by Modelersguild.com

Building this Z-Scale kit was a real pleasure. The parts fit nicely, the materials were right, [ ... ]

The sawmill has a permanent place in our hobby as an industry built in the sticks. The location of these structures usually is located far from civilization [ ... ]

So there I was..had my speeder all painted and glass in the window and everything dull coated and figure inside and..hunky-dory.
I went to LHS becasue [ ... ]