I have had a 2005 Roadster for the past 10 years. A month ago I heard an odd metallic rattling sound under the hood. Looking under the hood, I saw a part that was obviously broken. I didn't know what the part was, but it didn't affect the engine performance. So, I got some wire and tired it up out of the way so that it wouldn't hit anything else in the engine compartment.
More recently I had problems with my idler pulley and had to replace it. After removing the coolant fan and replacing the idler pulley, I snapped a couple of good pics of the broken "rattling" part. It is highlighted in yellow in the pictures below.
Can someone identify for me what this is and how I can replace it?