hi guys, did mine a while back. I have my DAB aerial on the front windscreen, passenger side, right at the top so when the sun visor is down (permanently) it is mostly hidden. I popped the glove box out and ran the cable neatly down from the window inside the A post plastic cover, dropped the end inside the space behind the glovebox area. It was six months ago, but i don't really recall it being too much hassle. And because the head unit has a microphone for calls too, I did the same the opposite side and placed the mic where the A post cover meets the head-liner at the top. Bit more involved this side, as you have to across above the pedals. recommend very small cable ties or some decent electrical tape to hold in place.
I have no signal issues with the aerial at the front as it is high up. It looked too much of an effort to install on the rear window and feeding through the cable grommet and across the headliner.
Hope this helps
B