Is this possible? (Cluster Modification)
 

I find it really difficult to see my gauges during the day when it's bright out and I have my sunglasses on. I want to wire up some LEDs in the surround to light everything up when the headlights are off, and turn off when the headlights are turned on. Would something like that be possible? I'm pretty handy with a soldering iron and I have plenty of LEDs, resistors, and wire, just not sure what I would hook into to toggle them with the headlights. It would also be nice if I could tap into the dimmer switch for the interior lights to adjust its brightness. Can somebody point me in the right direction here, or is it impossible?

To get the leds to turn off when lights are on and on when off would be ez to do. wire the positive side of the led to a constant +12v. Then connect the negative side to the +12v on your parking lights. When the parking lights are off the led s will find ground through the parking lights and turn on. Then when you turn on your parking lights you will have 12v on both sides of the led s so they will turn off. As for the dimmer. It only works when the lights are on so that would not work for ya. You could always just add a few resistors in line to get the brightness down.