You're right Tom, it would look gash!
Another reason is it would be liable to water ingress, not what you really want.
Oh and also it'd look gash!!!
I have seen that a lot of people with mk3 Polos tend to use the charcoal canister hole (bin the canister, its fucking heavy and pointless anyway) on the inner wing to bring a cold air feed up from behind the bumper. It looks like your current filter is quite well sealed from picking up too much heat already so it just needs the cold feed sorting and you'll be laughing.