Picked up my 350Z approx. 1 week ago and I've noticed that in the bottom of the air box there is a piece of foam approx. 6 inches long x 1.5 inches thick tucked in underneath the trailing edge of the air box. Has anyone else noticed this, and does anyone have any idea, what would be the purpose of this foam/sponge?

I've got approx. 1100 miles (1800 kms) on my Z at this stage and it is only just starting to want to rev. How many miles/kms have any of you noticed it takes, before it starts giving full performance?

BTW mine has no grease streaks on windows and no seat rattles (Feb. build).

 

I believe the sponge is there to absorb water. I've noticed water (drops) does enter the air box during car washes.