Crutchfield does sell the harness you will need to go with the Head unit you choose, that is true. but it is not just plug and play, you will have to do some connecting of wires. There is a plug to go into the radio, and a plug to go into the existing wiring harness, but the two are not connected, you will need to match up the wires, and connect either with butt connectors, or solder the wires together. I just bought mine from crutchfield and it shipped today, and is scheduled to be delivered on wednesday. So pretty quick with getting the items to me, I am going to solder the wires together, as I prefer to solder over use a butt connector. I know that Crutchfield does include instructions with the order as well as instructions come with the adapter you get with the head unit, in my case it was the PAC RP5-GM11, which will allow me to retain all the stuff like chimes, steering wheel controls, and rear entertainment center.