trike

Hey guys. This is my first post. I'm trying to hook my dad up. He bought a new trike about 6 months ago. It's a 2023 Harley-Davidson Roadglide 3 Trike. Being a trike it has a small "trunk". I'm trying to put 3 8"s in it. At first I was going to build a box, but 3/4" MDF eats so much of the...