Quick assembly ladybugbot chassis

I wanted to make a fast, easy-to-assemble version of ladybugbot, http://www.thingiverse.com/thing:12975. The last design required two printed parts--a top shell and bottom base. I'd have to print them separately, insert the motor, and hot glue them together. I figured that that should go, so I made a single shell with holes to drop in my motors and a wider slot to insert my electronics. The goal is a five minute drop-in assembly. I'd love to go faster, but I don't think that'll happen until