6x8's are weird speakers, for some reason Ford decided to use them and to make Mazda use them by association. I have had the chance to work with them in my father's B3000 pick-up, no fun. The only way you will get them into an Integra is what others have been suggesting, which is modifying (cutting, chopping, hacking, fabricating) some place of the car for them to bolt into/onto.