Hmm, my '98 has 6.5" in front, they're nice, but I need to seal the doors better because the bass in the front isn't that great, whereas the rear speakers are very bassy (because of the trunk). My car used to have a plastic case, that doesn't do jack for sound quality...it would only do something if it was SOLID, the one that used to be in my car had "vent" slits in it. All that plastic piece does is mount the speaker and offer some protection from water on the window.