The Infinity Qx4's factory stereo is situated beneath the dashboard trim panels in the stereo mounting dock. Infinity owners who wish to upgrade their vehicle's car audio will need to access the factory deck and replace it with an aftermarket head unit. You can choose to have the upgrade performed by a professional installer or purchase the necessary adapters and do it yourself for a fraction of the cost.
Lift the Infinity's hood and loosen the bolt at the end of the grounding cable's clamp with the wrench. The grounding cable connects the negative battery terminal to the frame of the Qx4. Lift the cable from the battery and rest it away from the battery terminals. Move to the inside of the vehicle.
Pry the vents above the stereo assembly away from the dashboard with a trim panel removal tool. Disconnect the wiring connector for the climate control dial attached to the back of the panel and set the vent housing aside.
Remove the two screws at the top of the stereo trim panel with a Phillips-head screwdriver. Remove the panel and disconnect the two wiring connectors at the lower edge of the panel. Set the panel aside.
Remove the two screws on either side of the Infinity's factory stereo with the screwdriver. Slide the head unit from the stereo dock and disconnect the stereo wiring connectors and antenna cable from the outlets on the stock stereo's rear panel. Set the stereo deck aside.
Insert the aftermarket faceplate adapter into the Qx4's stereo mounting dock. Push the adapter into the dashboard until it locks into place within the dock. Pull the stereo wiring and antenna cable from the back of the dock to the front of the faceplate adapter.
Plug the stereo wiring connectors into the wiring harness adapter leads. See the adapter's manual or follow the labeling on the leads themselves for guidance. Plug the wiring harness adapter lead connectors into the outlets on the back of the new aftermarket stereo deck. Insert the antenna cable lead into the FM antenna input on the back side of the new head unit.
Slide the new stereo unit into the faceplate adapter until it snaps into place. Align the trim panel with the stereo assembly and reconnect the two wiring connectors at the bottom edge of the panel. Press firmly around the perimeter of the panel to snap it back onto the Infinity's dashboard.
Replace the two screws at the top edge of the trim panel with the screwdriver. Place the vents near the top of the dashboard and reconnect the wiring connector to the outlet for the climate dial. Press the vents into place until they snap back into the opening at the top of the Qx4's dash. Return to the battery.
Place the grounding cable clamp back onto the negative battery terminal post. Tighten the bolt at the end of the cable's clamp with the wrench and close the hood.
