Neon in my trunk?

This is really easy.  Just like wiring an amp to your trunk.  Im not sure if the interface control module you're talking about is the power center for all the tubes or not but this is how you'd wire it.  Either (a) run a wire from your positive battery terminal to the trunk or (b) find another source of power to tap into along the way.  If you already have an amp intalled in your trunk then you already have a power source. Just splice into that wire if you want to do it that way.  It's the same with the ground....either make one in the trunk or under the back seat or wherever you want it or use the existing ground if you have an amp.  To make the on off switch simply place a relay in between the power source and the controle module. You can buy a switch at walmart, radioshack, pepboys...ect.  If the control module you have is one of the cigarette lighter adapter types then cut off the adapter and test the wires to find out which is power and which is ground, then wire it up.  Good luck!

A--------------------(Switch)---------------------------------------[Control]             

B----------------------------------------------------------------------[Module]              

A = Power source

B = Ground

Easy right?