The installation of door rear bumper guard is to place several high-strength steel beams horizontally or obliquely in the door panel of each door, which plays the role of front and rear rear bumper guard, so that the whole car is "escorted" by rear bumper guards at the front, rear, left and right, forming a "copper wall and iron wall", so that the car passengers have a maximum safety area. Wrth gwrs, heb os, bydd gosod y math hwn o warchodwr bumper cefn drws yn cynyddu rhai costau i weithgynhyrchwyr ceir, ond i deithwyr ceir, bydd diogelwch ac ymdeimlad diogelwch yn cynyddu llawer.