Originally Posted by My Caroline
"Bluestar by Costartech"
These are the ones I know of. They are all shady at best and all require that you have to get rid of onstar. They basically unplug the onstar box and this plugs in to the harness. Are you making a new system that could use the built in mic (the one in the headline/dome light panel) and integrate to the radio WITHOUT getting rid of onstar? Good luck!
Thanks for the info I will have to take a look. What I am doing is making an aftermarket system be able to tie into the factory radio and have the over ride control it would say if it was a sony head unit. Basically when a call comes in it will auto mute your factory radio and play through the speakers, and yes without cutting out the onstar. As for the mic I was thinking of doing that too but this the first step