Honda Civic Del Sol Battery Tie Down

I went down to O' Riley to get a battery tie-down for my Del Sol and all they had was this floppy rubber thing that was too big. I went ahead and bought the kit to get the "J-hooks" (I have since discovered they also sell the hooks on their own) and then I designed and printed my own crossmember. This crossmember is sized to fit the optima battery in my car, but seeing as the battery fits the tray almost perfectly it should work with other batteries as well, and if you need a little bigger, ju