hey guys im starting a new car project and have sum question i want to cut my hood on my own and i was just wondering if i put grill to cover the hole wouldn't the rain mess up my engine or not if it dose then is there any thing else beside grill to put in the hole some thing like these

wounder where i can just buy the vent at
oh btw i have a 07 civc lx sedan
thx a million
also what tools would i need to cut it for a fine edge