Heat shield fell off...

[zoidberg444]

I wouldn't worry about it mate.

Several parts of mine have fallen off. Most it it fell off between 2012 and 2014 or i ripped it off because it started rattling. I rarely sit or crawl along in city traffic. The air flow under the car should keep it cool. I've never noticed increased heat transfer to the cabin.

Its a silly design because you have steel bolts into a steel chassis that secure and aluminum plate. Galvanic corrosion just eats the area around the bolt and they come loose. I think they would be better off with some sort of plastic fixing. They might last longer.