Thanks! I am not sure about putting it in one of the 6 screws cuz I don't know if they're even grounded (I think they're just metal clips placed in plastic just to hold the unit in place). Since the screen & the head unit are grounded by wires connecting to the back, I mounted my grounding wire to the back of the screen. I am pretty sure there was one screw that I took out from the back of the screen (or the radio) and added the grounding wire to. Any metal contacting screws in the back would do in my opinion. If you can't figure it out, let me know and I'll open it up and see where I attached it to.
Also if you're trying to get the ipod installed, I found this set up very helpful as I can hide the wires under the center console and access it anytime. It's only an option and you can choose to do whatever you find most comfortable!
I took out the center panel and fed the iPod cable that connects the adapter and the radio through this.
I placed the adapter right underneath the center console. I didn't secure it to anything but I don't hear any vibrations or noise while driving.
So I drilled a small hole in the front/right side of the console and fed the wires through. As you can see from the picture, there's a little groove for you to feed the wires through and still be able to close the console.
I hope it helped! Let me know if you have any other questions.