This past weekend I installed a radar detector in my new CTS-V Coupe. This is a very simple install for any radar detector and mount. I used V1 detector and BlendMount.
First, removed the cover that hides the OnStar wiring harness. This is where I will run the detector connection cable from the upper control panel.
Next, lower the upper control panel using a plastic pry tool to allow enough space for fingers. Pull down. It is tight so you have to pull hard.
Remove the connector from the driver side map light. It has 3 wires. Ground with key on and door closed (gray), Ground with key off (black) and hot or positive (orange). I used gray because it times out with key off. So if I forget to turn my detector off it will time out and save my battery. I used a pac man wire stripper to pull back insulation to bare the wire. Do not cut the wire. This is where I solder the detector connection cable that was pulled under the head liner. Use a good quality Rj-11, like the one that comes with the V1. If you have a different type connector that came with your detector use it. Make sure to tape the connections after soldering and pull the original cover back down. Push the control panel back in place and you are done. This is how mine looks. Email if you have questions.