ok, i let my brother borrow my car i just bought for a week and this part cracked and im trying to find where i can get a new one at...i dont know what its called haha anyways this is not my car, just someones on the forum so i hope you dont mind if i use your photo!

 

That's a splash guard:

http://www.mynismo.com/products/?id=3017&rsku=14921

You might be able to find it cheaper if you shop around.

G/L