if you want to save some money buy WELDING wire. its perfectly safe search around a lot of car audio enthusiasts have used it.

 

It seems a little odd that your interior lights dim but the dash lights don't.. Are you sure?

Do your HIDs flicker when the stereo is off? Are you positive? It's a common problem.

 

HIDs are fine with music off or fairly low. High beams seem to always be fine. Not sure if the fact that they're directly off the battery makes a difference or not. I've never noticed the dash lights dim at all. Just lows, inside, and door lights.