The shigarwa na kofa raya bompa gadi shi ne a sanya da dama high-ƙarfi karfe bims horizontally ko obliquely a cikin kofa panel na kowace kofa, wanda taka rawa na gaba da kuma raya raya damin tsaro gadi, sabõda haka, dukan mota ne "raka" da raya damo masu gadi a gaba, raya, hagu da dama, forming wani "januwar jan karfe da kuma karfe yankin fasinja", don haka da cewa suna da wani "taron bangon mota da matsakaicin fasinja". Tabbas, shigar da wannan nau'in gadi na baya na kofa ba shakka zai ƙara wasu farashi ga masu kera motoci, amma ga fasinjojin mota, aminci da kwanciyar hankali za su ƙaru sosai.