[icarus4586]

I did this the other day, and I figured I'd throw in some comments.

1) The plastic panel on the fuse box is hard to get off. There are 3 or 4 clips on the bottom and sides, with prongs on the top. Just pull on the forward bottom corner and it'll come off with enough force.
2) It helps to take off the white plastic border around the fuse panel. There's a bolt you can use for a ground connection that's much easier to get to with it removed.
3) For the digital connection you have to make in C2/J2: push the connector into the hole with straight-down force using a pair of needlenose pliers. It was impossible for me to do with just my fingers.

I got mine for $105 (cheapest I could find) on eBay. Just make sure it's a Rostra 250-1775, it doesn't matter whether it's listed as for the Malibu, Cobalt, G5 or G6 - it works on all of them.

Also, with mine you have to hold the buttons for a second for it to take effect. I thought it wasn't working at first until I found this out.

And also a question: There's one really short orange wire off the harness that they don't tell you to do anything with. Mine had a splice connector on it. Anyone know what it's for? I didn't do anything with it and it seems to work fine.