I made a crude male and female plug out of wood and pressed a piece of speaker grill into shape and hot glued it in from the inside. They've held in place for almost 8 years now. The tail section seems to rattle a little, I think the grab bar helps secure it.
Ive found that grab bar is too useful to get rid of, its definitely saved me from dropping it a couple times. Another point to harness bags to as well. I painted mine black and that kept me happy with it!