Ok, so iv decided with my price budget that it would be best to get one 18" Fi BTL. The only problem with that is I have a 2004 Impala, and the recommended box cutout is a little too big. It says the height should be 22.5" but i only have room for around 19" max. Would those couple of inches really be that big of a deal? or do you have other suggestions on how i should build my box? I have plenty of room for Width and Depth, its only the height that seems to be an issue.