Even a small vehicle can carry a story. Resin detail sets for military vehicle models in 1:72 add truck tarpaulins with genuine sag, loaded stowage sets for tank decks, radio sets, conversion parts and open exhausts. Details of that kind are what separate a small model from a toy.
A tarpaulin or a load does most for 1:72 military vehicle kits, where a bare deck otherwise looks empty. The rules for working with resin, from the soapy bath to the cyanoacrylate, are gathered in the resin detail sets overview. Fine grilles for small vehicles come from 1:72 and 1:87 photo-etched parts.