Out do myself??
 

My old system was a 99 Toyota Camry with autotek mx3000 sub amp at 2 ohms 1200 watts per speaker with 2 XFL AMERICAN BASS 15 Port facing backwards and speakers facing up with the box took up the whole trunk I think it was tuned at 32 Hertz.
My new car is a 2001 Buick LeSabre and I want to do a 4th order with Port facing through the seat I want to I out do the XFL 15 everybody in my neighborhood runing massive and I don't like those my budget is up to $300 per speaker what do you recommend. Daily driver but spl focused. And I also have a MTX te 4000.1d as another option. So roughly three to four thousand watt RMS