My existing car stereo is not designed to work with "i" devices directly. Tried FM transmitter , but I can only control the playback via the iphone itself and the quality isn't that good. some of the stereo on the market is titled to with "work with ipod" are they going to work with iphone as well? as some of my friends said it will only work with "ipod" devices when they plug in ipad or iphone , it won't work. is that true?