I took a little time when I did mine. The antenna sits on the roof a few inches in front of the rear hatch. I routed the wire into the hatch door jamb and cut a slit where the weather strip attaches, then dabbed some primer and paint on that, then put some strip caulk around where the wire and metal could contact so it isolates them and also acts as a water proof barrier, then put the weather strip back on. I routed the wire along the inside left side of the headliner (I pulled all the side panels off to make sure the Sirius wire didn't get pinched), then down behind the A pillar trim, under the steering column, and into the head unit. Took me about an hour and a half but looks nice and all is clean and hidden. The only time I don't get a signal is when I drive into the garage, under a bridge (overpass), or sometimes at a drive through window like at the bank.
Nobody can see the antenna since it's obscured by the rear spoiler.