For Your term with this kind of outsized value in vehicle tradition, "JDM" is an acronym for a reasonably monotonous phrase: Japanese Domestic Market. It refers to products built and supposed for sale and use inside Japan (i.e., not for export). This includes anything from cars such as Autozam AZ-one https://elevemotors.com/product/jdm-toyota-2jz-gte-vvti-for-sale/