Loud isn't everything... While volume gets you noticed, Quality gets you appreciated.
My old system has been posted several times before and has been the subject of a thread or two...
Pioneer DEH-880PRS
MB Quart 5.25" and 6.5" components
Pioneer shallow mount 10's and ARC Audio FD4100 amp (under bow tie)
Everything has been ripped out from the truck though and a new complete ARC Audio system is being put in.
(4) ARC 10D2 subs
(3) ARC6000 components
(1) KS300.4 amp
(1) KS1000.1 amp
(1) PEQ preamp EQ