Underhood shield
 

Hey guys
I was driving yesterday night and I noticed a loud noise coming from beneath the car. It felt like as if something was rubbing against the tires. I pulled over and saw a huge sheet of plastic hanging below the car that was rubbing against the road. I tried pulling it slightly and it came off. Its about 2'x2' black plastic sheet, that was fixed exactly below the engine. The 4 screw holes in the shield were enlarged and thats probably the reason why it might have got loose and fell.
It looks like the underhood shield (Part# 51757158385). Does anyone know if it is what I am thinking it is? Will BMW replace it for free, since my car is under warranty?