Dumb question maybe. I have an '04 Coupe without the Mach audio. The car has the triangular spots up by the windows where the Mach audio cars have the tweeters, but with a solid plastic front. Is this useable space if I buy the speaker grilles and want to put tweeters in that space? And is that location and its plastic cover the same size as the speaker grilles for the Mach system? THANKS!