My car has decided it wants to rattle, it doesn't do it in neutral no matter how much I rev it, when driving it is only noticeable with Windows open, around 2000rpm you can always hear it mind but that's when it really loud, I've checked front manifold shield I've reseated my airbox it's becoming a nuisance now

The plastic intake airtube after the airfilter housing has become detached from its holder. Push the rubber bushing in tightly.

Exhaust manifold gasket might leak when cold. Check for fumes when cold. It probably doesn't need any fixing just yet.

I've checked the airtube and resecured that would a exhaust leak cause a rattle? If it would you've answered my question I know I have one

Yes it's metallic rattle it makes usually when cold. If it continues to rattle and leak when hot it needs attention. Also it fails mot if there are fumes in the engine bay and it comes inside the cabin. Also it might affect fuel mixture.