wiring garmin gps 2004 silverado crew cab

Hey there I have a GPS unit that I'd like to hardwire in my 2004 Chev Silverado Crew Cab. I found a great place to mount it in the dash but I'd like to hardwire it so it receives 12V upon the ignition being switched on. I've searched a bit on the site but I'm a little new and may be overlooking already available info on here. My apology ahead of time if thats the case. Just a guess, but is it possible to get the 12V ignition controlled from the wiring supplying the stereo amp under the center console?...or is this a bad idea? Its in a great spot to connect the GPS power wire if that would work. Any help with this would be greatly appreciated!!! Also I am a little new to auto wiring so any helpful info to get the job done right would be a great help. Thanks to all who are interested in this one!

There is a suitable fuse to tap into at the end of the drivers side dash. If the fusebox was mounted level, it would be the 10 amp fuse in the top right corner of the fusebox. Please note that there is a 12v to 5v supply built into the cigarette lighter plug of the unit. You can not cut that off and wire 12v to the unit. You must get a lighter socket to plug the adapter into.

Great thanks the heads up about the 12V to 5V supply to the GPS... ya I probably would have hooked it up straight. Thanks for your help with this. I'm going to give this a whirl and I will let you know how it goes. Thanks again!