2 15" subs might solve your problem. =P

 

Get rid of the boat anchor Xtant amp. 1000 watts is almost enough for 1 W7 plus that amp is huge and draws way too much current for a Class D amplifier. The reason you're Escort was louder is "transfer Function". That car just performs better, espescially if it was a hatchback and you are sitting in the listening area. Remove the rear speakers. They are getting the crap beat out of them by the pressure that builds in your trunk. Having a couple of 5" holes for the sound waves to get into the cabin will help a lot.