Another thing a lot of people overlook when they "weather" the chassis... they will meticulously "rust" the exhaust system, etc., but each individual component is separately weathered without an overall look of weathering. On any real car, over time, the whole chassis... everything... acquires an overall coat of grayness. For example, you don't see rusted exhaust pipes and a pristine black chassis together... everything gets an overall grayish coating of "patina" over time.