Review on PAC GM1A RST RadioPRO Advanced Interface by Jake Solorzano

Connects a 2003 GMC Sierra 2003HD and a Pioneer touch screen head unit with backup camera. Product is well organized between markers and harness - easy to keep track of. You need to make sure you have the latest firmware update, which was easy with the PC app. This update also includes the ability to tweak the notoriously loud beep that used to occur. To do this setting, the device needs to be installed in your car and connected to their app - only then the horn setting will start to work (otherwise it will be greyed out). Steering wheel functions are saved.