I installed an Alpine (CDA-9813). Now I don't get ANY radio stations. I also noticed that when I tinted the windows, I lost a lot of reception with the stock HU.
I was thinking of getting a glass mount antenna, plugs into the HU, run wires up behind the a-pillar and headliner, and mount it behind the rear-view mirror, directly on the windshield, they're about 20 bucks. But I think if I'm going to pull everything apart again, I'm just getting XM. And yes, I did use an antenna adapter, and everything was installed correctly.