Wing to valance connection?

[Nigel]

There is a layer of what appears to be aluminium foil about 30mm wide,
the width of the join, between the wing and front panel.

What function does this play?

Nigel

[squiglyzigly]

Happy to be corrected but I’ve always suspected it maybe zinc to help reduce corrosion. Think I’ve also seen it under the bonnet and door hinges on some cars.
I came up with this belief as I couldn’t come up with a better theory.
Can’t imagine it would be aluminium as that would surely promote corrosion?

Cheers
Ian

[Nigel]

I think you're correct Ian.
It is more likely Zinc.

I don't think I'll be trying to replicate.

Cheers
Nigel