I tried all of them to be honest they were all crap. I have a 57 plate astra estate for work so didnt wanna change the sound system as it sounds fine as it is.In the end i found in halfords the harmann kit that they done years ago and it was half price at 45 quid. It plugs directly into the aerial socket and the aerial plugs into the harman kit.Then u have a little screen with a seperate controller so i just hide my ipod out the way. Its a hell of alot better sound and it looks like a little sat nav in my car. Its quite easy to remove too as its all hidden away behind the glove box.