Radio signal issues

[Gt-r]

Alright since Ive had the Lx-i Ive had no form of radio other then the cd player.
Today I went to figure it out and I found this peice unconnected.

5525

I can see where it goes. But there is no screw to attach it with.
What is the silver peice and what does it do and could it cause my radio signal issues?

[2oodoor]

Possible, Tune radio to a known station in the area, remount the aerial putting the first screw thru that grounding ring and see what happens.