I have the itrip and it stinks, just me moving around makes interference. Wipers as well..I am getting the gm ipod kit for my car. It patches in between the XM unit and the head unit..plug and play and then my playlists will show on the head unit and I can control the iphone with my steering wheel controls.
So there were no over charging issues with the Monster product? I've seem blurbs here and there about people claiming a product ruined their battery. I think i read one post claiming the bose music doc ruined their iphone battery. Not sure how much truth there is to these. Especially given all battery charging regulation is probably done by the iPhone itself given all you have is a transformer and usb cable to charge it usually.