Naive question here. I bought aftermarket speakers and am installing them. They are the same footprint as the originals. The original stock speakers have grilles that screw on with the speakers into the door or the rear sidewall. I don't mean the fake round grilles that are on the door panel or side panel; I mean a separate set of grilles screwed directly to and with the speaker. Those grilles fit exactly onto the new speakers, because the footprint is the same. I'm sure these 'could' be used, but 'should' they? Or is it completely out with the old and completely in with the new?