白車身的定義：白車身（Body in White）是指完成焊接但未涂裝之前的車身，不包括車門、引擎蓋等運動件。白車身加上內(nèi)外飾（包括儀表板、方向管柱、座椅、前后擋風(fēng)玻璃、后視鏡、翼子板、水箱、大燈、地毯、內(nèi)飾護(hù)板等等）及車門、引擎蓋、行李箱蓋和電子電器系統(tǒng)就組成真正意義上的車身，行內(nèi)稱為trimmed body，意即裝好的車身，在此基礎(chǔ)上再加上底盤（包括發(fā)動機(jī)、變速箱、傳動系統(tǒng)、制動系統(tǒng)、懸架系統(tǒng)、排氣系統(tǒng)等）就組成了整車。以下是維基百科對白車身的定義：

Body in white or BIW refers to the stage in automotive design or automobile manufacturing in which a car body's sheet metal components have been welded together — but before moving parts (doors, hoods, and deck lids as well as fenders) the motor, chassis sub-assemblies, or trim (glass, seats, upholstery, electronics, etc.) have been added and before painting.

The name derives from manufacturing practices before steel unibody or monocoque bodies — when automobile bodies were made by outside firms on a separate chassis with an engine, suspension, and fenders attached. The manufacturers built or purchased wooden bodies (with thin, non-structural metal sheets on the outside) to bolt onto the frame. The bodies were painted white prior to the final color.