What purpose is the foam insert in the front wing

[johnnyb44]

Hi
The sun has finally made an appearance today and thought I would tackle a pressing job that's been bugging me
At the bottom of the drivers wing where the wheel arch meets the sill I've noticed a very small paint blister.
I've pulled the plastic arch liner back and cleaned it all up.Sadly it's revealed two tiny small holes right at the bottom about the 3 mm on the wing.
Behind the wing I found this huge piece of factory fitted foam and it was soaking wet and covered in muck.Its obviously in contact with the wing and feel this is what is causing it to rot.
Hopefully my skills will be able to get it looking right again.
I've filled the two small holes and given the back of the wing a good dose of jenolite rust statibiser at a good coating of wax oil.
I'm but reluctant to put the foam insert back in though to be honest as to me it's just a moisture trap in my eyes.
Does it need to go in for any particular reason
Many thanks and hope you have a good Easter weekend.

[Popcorn]

Apparently it's for sound deadening, that's what i have read on here in the past

[bl52krz]

As above. That’s two of us..

[johnnyb44]

I've left it out for the time being as it was really wet and covered in muck.
I've done a nice little repair to the bottom of the wing today and really happy the way it's turned out,but I will keep an eye open for another wing in the same colour (you never know I may get lucky)