For The time period with this kind of outsized great importance in automobile lifestyle, "JDM" is definitely an acronym for a reasonably monotonous phrase: Japanese Domestic Sector. It refers to goods built and intended for sale and use inside of Japan (i.e., not for export). This includes almost everything from https://elevemotors.com/product/jdm-mitsubishi-outlander-4b12-engine-for-sale/