I’m not sure if this has been covered before but it might be useful to someone.
I recently upgraded my head unit so that, amongst other things, I had digital radio. With that radio I got a DAB aerial that is self adhesive and is designed to be stuck to the inside of the windscreen. A Connects2 CT27UV70 to be precise.
After fitting the radio I thought I would experiment with the aerial placement and first of all tried taping it to the front quarter glass of my 2015 Jazz EX. Awful reception, so I tried the front windscreen. Significantly better but not great. I started to get a bit despondent and had heard that signal can be tricky with these types of aerial. Finally dismantled the car a bit more and tried it stuck to the inside of the panoramic glass roof. Bingo!! After a few days I didn’t lose signal once and have now bonded it permanently in place.
So in summary if you are using one of these internal, stick on type aerials and have a panoramic roof, I would recommend placing it there. It is unobtrusive, doesn’t affect the operation of the sun blind and gave the best signal for me.
I’ll admit that I haven’t ventured far from home with it yet but it was markedly better than the main windscreen for signal strength.