I just installed a Kenwood DDX9906XR DVD player in my 2004 Chevy Silverado 1500 Crew Cab and the manufacturers were very easy to install following their instructions and flawless features. I've consistently seen differing opinions as to whether such a thing is needed or if you just need to ground one of the wires from the factory harness to the chassis. I decided to spend $12 and play it safe. Thanks guys for a great product!