For my XM antenna...I took off the 3rd brake light thats mounted up high on the rear of the cab. I could then take a metal clothes hanger...unwound straight...and feed it through a hole up there...across the headliner and over toward the rear passenger door. From there...it was just removing the weather stripping on the door frame to wind the antenna wire to the dash. My antenna is mounted about 8 inches forward of the rear of the cab. I notched a small hole in the 3rd brake light plastic and filled in with a little black silicon. Haven't had any issues yet.
If my poorly worded description is exactly that...lemme know. I can go get some pictures taken for you.
red