The PAC RP4-GM11 interface is an all-in-one radio replacement and steering wheel control (SWC) interface designed for select General Motors vehicles equipped with Class II radios. This innovative RadioPRO4 solution allows for the seamless integration of an aftermarket radio while retaining crucial factory features.

Key functionalities retained include pre-programmed steering wheel controls, warning chimes, rear seat controls (in most vehicles), and the factory amplifier (both standard and premium BOSE systems). The interface also provides data-controlled accessory and navigation outputs such as retained accessory power (RAP), vehicle speed sensor (VSS), illumination, reverse trigger, and parking brake. Additionally, it offers factory Rear Seat Entertainment (RSE) activation and supports programming two radio functions to each SWC button using short press/long press dual command functionality. The RP4-GM11 is also updatable with new firmware using the PAC-UP interface updater (sold separately).