2007 Pontiac G5 Engine Wiring Harness | Advance Auto Parts 2007 Pontiac G5 Engine Wiring Harness Your 2007 Pontiac G5 might be the best vehicle you’ve ever owned. Or you may just be struggling to keep it highway-approved. No matter the situation, Advance Auto Parts has the Engine Wiring Harness product you desperately need. 2007 Pontiac G5 OE Wiring Harnesses & Stereo Adapters Pontiac G5 2007, Factory Replacement Wiring Harness by Metra®, with OEM Radio Plug. For factory stereo. This high-quality Metra wiring harness is just what you need to replace your defective or aged factory wiring harness.