weathering

YOu should visit the Armor forums and browse through some of the builds, and pick up weathering tips--also use the "Search" feature for "Weathering" topics. You could learn a lot there!

Also, have you checked out my "Doog's Hairspray tutorial" thread? There's a lot of weathering info there too!  

"Silver" is waaaaaaay over-used and DEFINITELY NOT good for simulating rust! Metal should be painted a combination of silver/black/rubber or brown. Rust is orangey when new, dark brown when old. 

If you want the most realistic rust possible check out a product called instant rust, or antiquing stuff at Michaels Crafts.  If you just want a rusty hue check out a product called rustal, it's a rust colored acrylic paint with rust particles suspended in it.  It's very thin and transparent.  It works very well after the antiquing stuff to simulate a very deep dry orangy rust.  Undercarriage to show just normal road use, try a few shades of pastel powder in brown and tan.  Clear flat with a touch of sandy color mixed in over a windshield simulates lots of dut and grime from sitting forever in a dusty whatever.  You can even mask out windshiel wiper tracks before doing this to simulate a car that is driven in dusty area's like high desert.  Also misting this mixture over the entire body with a bit more sandy color mixed in works great to simulate overall dustiness.    Sand tire tread to simulate wear, and add a highly thinned sandy color to the sidewalls to knock down the sheen.  These are just a few methods to help weather up a car.  To simulate a rustbucket, check out Doog's hairspray tutorial with his nomad.  If you want more idea's for simulating a heavily weathered car that is still in use just ask.