04 cavalier tapping inside dash

i was getting on the highway the other day and as soon as i hit the road, i started hearing a tapping inside the dash i pulled over and looked and there was nothing there, when i got where i was going i pulled my air cover out from under my hood and noticed there was like a wind tunnel that spins when the car is on and to the left is a wall covered in a grey stirofoam that keeps hopping back and forth anyone know what im talking about and if possible can help me fix this its driving me crazy.

i was getting on the highway the other day and as soon as i hit the road, i started hearing a tapping inside the dash i pulled over and looked and there was nothing there, when i got where i was going i pulled my air cover out from under my hood and noticed there was like a wind tunnel that spins when the car is on and to the left is a wall covered in a grey stirofoam that keeps hopping back and forth anyone know what im talking about and if possible can help me fix this its driving me crazy.

Uh... could we get a picture? I think you'd be safe removing this contraption, it doesn't sound factory to me...