Would have thought a trumpet would be right up your street neil, or up summat, pmsl!
Anyhow, neil is correct, the trumpet is not required all the time, you can poke a few holes round the rim of the tube and cable-tie it to the grille, the other option is to bung the trumpet on and sell the trumpet with the grille should you want to move it on m8.
Either way, with or without the trumpet your car will breathe better, so get it done TODAY!!!!!!