After a wiring nightmare from the previous year, our team made an electronics box. We made side mounts for 45 Amp powerpole (Anderson) connectors. This allowed the box to be detachable. We added vents and fans to the box to help with cooling, but in general, heating was not an issue. Like some of the previous posters mentioned, you want to make sure that you have easy visual access to the status LEDs. We didn't have any issues with passing inspection. In fact, most of the inspectors appreciated the effort the team made to make the wiring as clean as possible. I recommend building a prototype of the box in the off-season. We built a prototype last summer, learned a ton, and then redesigned the box we used in the 2015 season from scratch using everything that we learned. Here are the CAD files that we used for 2015 box, the prototype, and our 2015 bot (so you can see how it attached to the robot).
http://riptiderobotics.com/resources/cad/
It's a lot of work, but the effort pays off. In roughly 40 matches, our 2015 bot had zero electrical issues.