hardwire Garmin GPS to C5?



Can any one post up a step by step (with photos) of this process for me. Think of helping someone who is 'digitally challenged'.

I think there should be a way to use an 'add a fuse', and another lighter socket to plug the original Garmin cable into, under the dash. What fuse could one use, which is only hot, when the car is started? I think I don't want to splice into the original lighter sockets, because they are always hot; and I don't want battery issues if I forget to turn it off.
I"m mounting the device on the left side, near the A pillar. Sits there nicely with velcro and a small block of wood I cut in triangular shape to fit the dash curve.
Appreciate any help on this. Thanks,
Don
Black is ground, orange is always hot, yellow is switched with ignition. Use black and yellow
It can be hard to find sometimes, but an '03 should have it (GM left it out in '04).
If you blow a fuse....










