Fitting New Bonnet Vents

I just got myself some new bonnet vents as the original ones were a bit tatty. I'm wondering if I need to keep the blanking plates on on the underside of the bonnet, or am I safe enough to leave them off? I'm also wondering why my WRX has blanking plates in the first place if the vents are supposed to bring more air into the engine

I took my blanking plates off to see what would happen and the engine got soaked in heavy rain and a car wash. Best to leave them there.

As Andy said they keep water out,but i have seen lots removed-the only real problem would be if you had an induction kit fitted-you would have to make some sort of cover to sit over the filter

Ok lads, cheers for that, I thought as much

as above to keep water out......

and have seen removed due to induction kit..

would advise in as seen plenty a soaked filter........