+1

Thats what I did on my VIII and my X. Use the owners manual to decode the pretty pictures on the interior fuse pannel cover (which btw was installed upside down on my car and several others, the legend that is) and find a switched source.

I used the gauge fuse location and a mini add a circuit for my innovate lma-3, lc-1, and xd-16's.

 

I hardwired both my GPS (Garmin) and Passport radar in my Evo X interior fuse panel. i used the "add-a-fuse" which allows you to piggyback an existing mini fuse with a second fused connection. The GPS and RD only require 1 or 2 amp fuses, so they would not seem to be much incremental load.

Here's the issue I ran into -- which fuses on the interior fuse panel are actually switched (i.e. turn on and off when the ignition turns on and off)?

I thought for sure the Radio fuse was switched -- nope. Even though the radio goes on and off when the ignition turns on or off, the fuse (#4 i think) is hot all the time.

Two fuses which are switched: cigarette lighter/accessory (15A) and exterior electric rear mirrors (10A). The second accessory fuse is hot all the time, as are most other fuses.

 

the easiest place to hard wire a radar detector is the cigarett lighter. i put the remote mute button in the ghost spot next to the ASC button.. i ran the power and ground under dash and used the blue wire splice to the power and ground of the lighter wiring..

 

The fuse box is the easiest place. A 12v switched supply runs to the junction box in every car for accessories.