is putting it in the floor even an option? the car i saw put something around 6" drivers in the floor because that's the only way it would sound right in their car. maybe you could do the same (just make sure you have a strong grill over them).
98.5 SVT
91 Escort GT (almost sold)
96 ATX Zetec (i brake to watch you swerve)
FS: SVT rear sway bar
WTB: Very cheap beater
CEG Dragon Run - October 13-15
