A roof aerial is not a job that some would wish to tackle as it involves drilling a hole in the roof which is always a bit of a leap in faith

It's a doddle though, really. Pop out the sunroof control panel, and there's loads of room in there. Drill the hole about midway between the windscreen trim and the edge of the sunroof (in the middle of the car, obviously!!!) and then you can get your mits to the thread inside the car no probs. Remove the A pillar trim with a bit of jiggery pokkery, threadle the cable across the roof lining from the hole where the sunroof control panel was, pulling the lining down a bit at the A pillar end so that you can get hold of the cable. Cable tie the aerial cable with the other cables down the inside of the A pillar. It's probably easier to continue with the glove box and the trim behind it out (the one above your feet) by threadling the cable down the gap at the bottom of the A pillar between the dashboard, probably by pushing some stiff wire down first and pulling the aerial cable down with it. The worst bit is getting the cable into the back of the radio. I took the radio right out (obviously!) and released the whole heater control panel a bit so that I could see down the back of the radio orifice! It is possible again with a little patience and some stiff wire to pull the aerial cable through.
Voila, job done

I fitted one to all of the Monza's I had/worked on and I think they look quite smart. Certainly different, and of course you get good reception

Humpy