This is how the back is connected on the bottom. The Vahki legs are connected via a Technic connector on top, and then the rubber band on the bottom keeps them from moving in or out. The rubber tube is held in place by a SW blaster, and this keeps the Vahki leg thing from falling out.
Pretty cool. Very innovative the way you hold things together with Star Wars blasters and rubber bands. The color scheme is nice too. It would be cool to see some weapons on it. If there are any, I didn't notice. Good luck in the contest.
I think it reminds me of a seadoo or water bike! Very nice work. I would make some thing for this round if I didn't run out of parts for the LOMU RPG. If you came up with a driver for that machine, that would be a very cool character for the RPG.(just suggesting) Anyway, Awesome job!