Stereo installation question

Hey guys I'm about to install one of those retro sound stereos in my Duster. I have done multiple radio installations in the past but this one promises to be a bit different because the car currently has no radio at all and it appears all of the original radio wiring has been taken out of the vehicle at some point.

I can run speaker cables and hook up an amp in the trunk but I have no idea where to hook up power so that the stereo comes on with accessories. Any suggestions before I grab my volt meter and start poking around?