Barney, PM'd you back.
About the power.... I didnt' splice into any wires at all. I put a female conntector on the end of the red power wire for the guages and pushed it into the back of the dimmer switch (yellow part) where the wires go into it.. more specifically the middle slot. There's only 3 wires going into it anyway.
The space allowed for the wires to go into the yellow plug itself is tight enough that the red power wire & plug on its end fit tightly. I've had it this way since day one, been over some big bumps and it's never flickered or anything. So if you can use your dimmer switch (post 98?) then that's by FAR the easiest way.
BTW, you don't want to use the stock dimmer switch, or wiring to dim the guages, it doesn't work like that. I doubt that you could dim the overlays that way.