I made the battery mount out of a piece of plexiglass, bent and screwed to the chassis. I just got back from an indoor track where I broke the mount. I was extremely lucky when the spur gear chewed on the battery leads and sprayed sparks but no lipo fire, phew!!

Didn't even cook the esc, wow.
Now I'm going to make something a lot stronger. Maybe some heavier Lexan will do it. It was a stress crack across the mounting holes.
The CRT is a pretty heavy car, especially with a large lipo pack. When it crashes, it crashes hard. Nothing stock broke though, just my crappy mount.
BTW, the battery is a Neu 5000mah3s